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  • 1.
    Adamo, A.
    et al.
    Stockholm Univ, Oskar Klein Ctr, Dept Astron, AlbaNova Univ Ctr, SE-10691 Stockholm, Sweden..
    Ryon, J. E.
    Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA.;Univ Wisconsin Madison, Dept Astron, Madison, WI USA..
    Messa, M.
    Stockholm Univ, Oskar Klein Ctr, Dept Astron, AlbaNova Univ Ctr, SE-10691 Stockholm, Sweden..
    Kim, H.
    Gemini Observ, La Serena, Chile..
    Grasha, K.
    Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA..
    Cook, D. O.
    CALTECH, Pasadena, CA 91125 USA..
    Calzetti, D.
    Univ Massachusetts, Dept Astron, Amherst, MA 01003 USA..
    Lee, J. C.
    Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA.;CALTECH, Spitzer Sci Ctr, Pasadena, CA 91125 USA..
    Whitmore, B. C.
    Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA..
    Elmegreen, B. G.
    IBM Corp, TJ Watson Res Ctr, Div Res, Yorktown Hts, NY USA..
    Ubeda, L.
    Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA..
    Smith, L. J.
    European Space Agcy, Space Telescope Sci Inst, Baltimore, MD USA..
    Bright, S. N.
    Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA..
    Runnholm, A.
    Stockholm Univ, Oskar Klein Ctr, Dept Astron, AlbaNova Univ Ctr, SE-10691 Stockholm, Sweden..
    Andrews, J. E.
    Univ Arizona, Dept Astron, Tucson, AZ USA..
    Fumagalli, M.
    Univ Durham, Inst Computat Cosmol, Durham, England.;Univ Durham, Ctr Extragalact Astron, Dept Phys, Durham, England..
    Gouliermis, D. A.
    Heidelberg Univ, Zentrum Astron, Inst Theoret Astrophys, Albert Ueberle Str 2, D-69120 Heidelberg, Germany.;Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany..
    Kahre, L.
    New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA..
    Nair, P.
    Univ Alabama, Dept Phys & Astron, Tuscaloosa, AL 35487 USA..
    Thilker, D.
    Johns Hopkins Univ, Dept Phys & Astron, Baltimore, MD 21218 USA..
    Walterbos, R.
    New Mexico State Univ, Dept Astron, Las Cruces, NM 88003 USA..
    Wofford, A.
    Univ Nacl Autonoma Mexico, Inst Astron, Unidad Acad Ensenada, Km 103 Carr Tijuana Ensenada, Ensenada 22860, Baja California, Mexico..
    Aloisi, A.
    Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA..
    Ashworth, G.
    Univ Durham, Inst Computat Cosmol, Durham, England.;Univ Durham, Ctr Extragalact Astron, Dept Phys, Durham, England..
    Brown, T. M.
    Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA..
    Chandar, R.
    Univ Toledo, Dept Phys & Astron, Toledo, OH 43606 USA..
    Christian, C.
    Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA..
    Cignoni, M.
    Univ Pisa, Dept Phys, Largo B Pontecorvo 3, I-56127 Pisa, Italy.;INFN, Largo B Pontecorvo 3, I-56127 Pisa, Italy..
    Clayton, G. C.
    Louisiana State Univ, Dept Phys & Astron, Baton Rouge, LA 70803 USA..
    Dale, D. A.
    Univ Wyoming, Dept Phys & Astron, Laramie, WY 82071 USA..
    de Mink, S. E.
    Univ Amsterdam, Astron Inst Anton Pannekoek, Amsterdam, Netherlands..
    Dobbs, C.
    Univ Exeter, Sch Phys & Astron, Exeter, Devon, England..
    Elmegreen, D. M.
    Vassar Coll, Dept Phys & Astron, Poughkeepsie, NY 12601 USA..
    Evans, A. S.
    Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA.;Natl Radio Astron Observ, Charlottesville, VA USA..
    Gallagher, J. S. , I I I
    Grebel, E. K.
    Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Herrero, A.
    Inst Astrofis Canarias, Tenerife, Spain.;Univ La Laguna, Dept Astrofis, Tenerife, Spain..
    Hunter, D. A.
    Lowell Observ, 1400 W Mars Hill Rd, Flagstaff, AZ 86001 USA..
    Johnson, K. E.
    Univ Virginia, Dept Astron, Charlottesville, VA 22903 USA..
    Kennicutt, R. C.
    Univ Cambridge, Inst Astron, Cambridge, England..
    Krumholz, M. R.
    Australian Natl Univ, Res Sch Astron & Astrophys, Canberra, ACT, Australia..
    Lennon, D.
    ESA, European Space Astron Ctr, Madrid, Spain..
    Levay, K.
    Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA..
    Martin, C.
    CALTECH, Pasadena, CA 91125 USA..
    Nota, A.
    European Space Agcy, Space Telescope Sci Inst, Baltimore, MD USA..
    Ostlin, G.
    Stockholm Univ, Oskar Klein Ctr, Dept Astron, AlbaNova Univ Ctr, SE-10691 Stockholm, Sweden..
    Pellerin, A.
    SUNY Coll Geneseo, Dept Phys & Astron, Geneseo, NY 14454 USA..
    Prieto, J.
    Princeton Univ, Dept Astrophys Sci, Princeton, NJ 08544 USA..
    Regan, M. W.
    Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA..
    Sabbi, E.
    Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA..
    Sacchi, E.
    Bologna Univ, Dept Phys & Astron, Bologna, Italy.;Osservatorio Astron Bologna, INAF, Bologna, Italy..
    Schaerer, D.
    Univ Geneva, Observ Geneve, Geneva, Switzerland..
    Schiminovich, D.
    Columbia Univ, Dept Astron, New York, NY 10027 USA..
    Shabani, F.
    Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany..
    Tosi, M.
    Osservatorio Astron Bologna, INAF, Bologna, Italy..
    Van Dyk, S. D.
    Osservatorio Astron Bologna, INAF, Bologna, Italy..
    Zackrisson, Erik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Legacy ExtraGalactic UV Survey with The Hubble Space Telescope: Stellar Cluster Catalogs and First Insights Into Cluster Formation and Evolution in NGC 6282017Inngår i: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 841, nr 2, artikkel-id 131Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We report the large effort that is producing comprehensive high-level young star cluster (YSC) catalogs for a significant fraction of galaxies observed with the Legacy ExtraGalactic UV Survey (LEGUS) Hubble treasury program. We present the methodology developed to extract cluster positions, verify their genuine nature, produce multiband photometry (from NUV to NIR), and derive their physical properties via spectral energy distribution fitting analyses. We use the nearby spiral galaxy NGC 628 as a test case for demonstrating the impact that LEGUS will have on our understanding of the formation and evolution of YSCs and compact stellar associations within their host galaxy. Our analysis of the cluster luminosity function from the UV to the NIR finds a steepening at the bright end and at all wavelengths suggesting a dearth of luminous clusters. The cluster mass function of NGC 628 is consistent with a power-law distribution of slopes similar to-2 and a truncation of a few times 10(5) M-circle dot. After their formation, YSCs and compact associations follow different evolutionary paths. YSCs survive for a longer time frame, confirming their being potentially bound systems. Associations disappear on timescales comparable to hierarchically organized star-forming regions, suggesting that they are expanding systems. We find massindependent cluster disruption in the inner region of NGC 628, while in the outer part of the galaxy there is little or no disruption. We observe faster disruption rates for low mass (<= 10(4) M-circle dot) clusters, suggesting that a massdependent component is necessary to fully describe the YSC disruption process in NGC 628.

  • 2. Adamo, A.
    et al.
    Östlin, G.
    Zackrisson, E.
    Papaderos, P.
    Bergvall, Nils
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Rich, R. M.
    Micheva, G.
    Star cluster formation and evolution in Mrk 930: properties of a metal-poor starburst2011Inngår i: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 415, nr 3, s. 2388-2406Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present the analysis of the large population of star clusters in the blue compact galaxy (BCG) Mrk 930. The study has been conducted by means of a photometric analysis of multiband data obtained with the Hubble Space Telescope (HST). We have reconstructed the spectral energy distributions of the star clusters and estimated the age, mass and extinction for a representative sample. Similar to previous studies of star clusters in BCGs, we observe a very young cluster population with 70 per cent of the systems formed less than 10 Myr ago. In Mrk 930, the peak in the star cluster age distribution at 4 Myr is corroborated by the presence of Wolf-Rayet spectral features, and by the observed optical and infrared (IR) line ratios [OIII]/H beta and [Ne III]/[Ne II]. The recovered extinction in these very young clusters shows large variations, with a decrease at older ages. It is likely that our analysis is limited to the optically brightest objects (i.e. systems only partially embedded in their natal cocoons; the deeply embedded clusters being undetected). We map the extinction across the galaxy using low-resolution spectra and the H alpha-to-H beta ratio, as obtained from ground-based narrow band imaging. These results are compared with the extinction distribution recovered from the clusters. We find that the mean optical extinction derived in the starburst regions is close to the averaged value observed in the clusters [more than 80 per cent of the systems have E(B - V) <= 0.2mag], but locally, do not trace the more extinguished clusters. Previous HST studies of BCGs have revealed a population of young and extremely red super star clusters. We detect a considerable fraction of clusters affected by a red excess also in Mrk 930. The nature of the red excess, which turns up at near-IR wavelengths (I band and longwards), remains unknown. We compare the cluster formation history and the star formation history, the latter derived from the fit of spectral population synthesis models to the spectra. We find a general agreement between the two independently estimated quantities. Using the cluster properties, we perform a study of the host environmental properties. We find that the cluster formation efficiency (the fraction of star formation happening in clusters) is significantly higher, suggesting a key role of the environment for the formation of these massive objects.

  • 3.
    Agarwal, Bhaskar
    et al.
    Yale Univ, Dept Astron, 52 Hillhouse Ave,Steinbach Hall, New Haven, CT 06511 USA..
    Johnson, Jarrett L.
    Los Alamos Natl Lab, Theoret Div X, Los Alamos, NM 87545 USA..
    Zackrisson, Erik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Labbe, Ivo
    Leiden Univ, Leiden Observ, NL-2300 RA Leiden, Netherlands..
    van den Bosch, Frank C.
    Yale Univ, Dept Astron, 52 Hillhouse Ave,Steinbach Hall, New Haven, CT 06511 USA..
    Natarajan, Priyamvada
    Yale Univ, Dept Astron, 52 Hillhouse Ave,Steinbach Hall, New Haven, CT 06511 USA..
    Khochfar, Sadegh
    Univ Edinburgh, Inst Astron, Royal Observ, Edinburgh EH9 3HJ, Midlothian, Scotland..
    Detecting direct collapse black holes: making the case for CR72016Inngår i: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 460, nr 4, s. 4003-4010Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We propose that one of the sources in the recently detected system CR7 by Sobral et al. through spectrophotometric measurements at z=6.6 harbours a direct collapse black hole (DCBH). We argue that the LW radiation field required for direct collapse in source A is provided by sources B and C.By tracing the LW production history and star formation rate over cosmic time for the halo hosting CR7 in a ACDM universe, we demonstrate that a DCBH could have formed at z similar to 20. The spectrum of source A is well fit by nebular emission from primordial gas around a BH with MBH similar to 4.4x10(6)M(circle dot) accreting at a 40 per cent of the Eddington rate, which strongly supports our interpretation of the data. Combining these lines of evidence, we argue that CR7 might well be the first DCBH candidate.

  • 4.
    Ahlvind, Julia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    The Almighty Quasar — Destroyer of Worlds2019Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    In the study of habitability of terrestrial exoplanets, both life-supporting conditions and the prevalence of transient life-threatening events need to be considered. One type of hazardous effect that has so far not received much attention is the thermal effect of a nearby active galactic nucleus (AGN), or in this particular case, the class of the AGN known as a quasar. In this work we investigate the thermal effect from a quasar by calculating the number of habitable terrestrial planets (HTP) in an elliptical or bulge-dominated galaxy, that goes extinct when exposed to the quasar radiation in a limited wavelength range. This is done by approximations and modelling along with pre-existing formulas and data from earlier publications. As a result, the influence by a quasar during the time span of quasar activity will have a less significant impact on the habitability in solar-type stellar systems than expected. Assuming tQSO = 108 yrs of quasar activity, results in the number of affected HTP, ≈ 1 × 105, 9 × 105 and 4 × 108 for isotropic spherical radiation and ≈ 1 × 106, 8 × 106 and 3 × 109 for a double-conical radiation. In terms of stellar mass fraction, ≈ 1.3%, 1.0%, 0.4% for isotropic radiation and ≈ 12.8%, 9.5%, 3.8% for conical, is affected. The results of this work are hoped to provide a rough estimation of the thermal impacts of a quasar on the habitability as well as to point out the most important parameters when considering this model.

  • 5. Alecian, E.
    et al.
    Kochukhov, Oleg
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Neiner, C.
    Wade, G. A.
    de Batz, B.
    Henrichs, H.
    Grunhut, J. H.
    Bouret, J. -C
    Briquet, M.
    Gagne, M.
    Naze, Y.
    Oksala, M. E.
    Rivinius, T.
    Townsend, R. H. D.
    Walborn, N. R.
    Weiss, W.
    First HARPSpol discoveries of magnetic fields in massive stars2011Inngår i: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 536, s. L6-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the framework of the Magnetism in Massive Stars (MiMeS) project, a HARPSpol Large Program at the 3.6m-ESO telescope has recently started to collect high-resolution spectropolarimetric data of a large number of Southern massive OB stars in the field of the Galaxy and in many young clusters and associations. We report on the first discoveries of magnetic fields in two massive stars with HARPSpol - HD 130807 and HD 122451, and confirm the presence of a magnetic field at the surface of HD 105382 that was previously observed with a low spectral resolution device. The longitudinal magnetic field measurements strongly vary for HD 130807 from similar to-100 G to similar to 700 G. Those of HD 122451 and HD 105382 are less variable with values ranging from similar to-40 to -80 G, and from similar to-300 to -600 G, respectively. The discovery and confirmation of three new magnetic massive stars, including at least two He-weak stars, is an important contribution to one of MiMeS objectives: the understanding of the origin of magnetic fields in massive stars and their impact on stellar structure and evolution.

  • 6. Alecian, E.
    et al.
    Kochukhov, Oleg
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Petit, V.
    Grunhut, J.
    Landstreet, J.
    Oksala, M. E.
    Wade, G. A.
    Hussain, G.
    Neiner, C.
    Bohlender, D.
    Discovery of new magnetic early-B stars within the MiMeS HARPSpol survey2014Inngår i: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 567, s. A28-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Context. The Magnetism in Massive Stars (MiMeS) project aims at understanding the origin of the magnetic fields in massive stars as well as their impact on stellar internal structure, evolution, and circumstellar environment. Aims. One of the objectives of the MiMeS project is to provide stringent observational constraints on the magnetic fields of massive stars; however, identification of magnetic massive stars is challenging, as only a few percent of high-mass stars host strong fields detectable with the current instrumentation. Hence, one of the first objectives of the MiMeS project was to search for magnetic objects among a large sample of massive stars, and to build a sub-sample for in-depth follow-up studies required to test the models and theories of fossil field origins, magnetic wind confinement and magnetospheric properties, and magnetic star evolution. Methods. We obtained high-resolution spectropolarimetric observations of a large number of OB stars thanks to three large programs (LP) of observations that have been allocated on the high-resolution spectropolarimeters ESPaDOnS, Narval, and the polarimetric module HARPSpol of the HARPS spectrograph. We report here on the methods and first analysis of the HARPSpol magnetic detections. We identified the magnetic stars using a multi-line analysis technique. Then, when possible, we monitored the new discoveries to derive their rotation periods, which are critical for follow-up and magnetic mapping studies. We also performed a first-look analysis of their spectra and identified obvious spectral anomalies (e. g., surface abundance peculiarities, Ha emission), which are also of interest for future studies. Results. In this paper, we focus on eight of the 11 stars in which we discovered or confirmed a magnetic field from the HARPSpol LP sample (the remaining three were published in a previous paper). Seven of the fields were detected in early-type Bp stars, while the last field was detected in the Ap companion of a normal early B-type star. We report obvious spectral and multiplicity properties, as well as our measurements of their longitudinal field strengths, and their rotation periods when we are able to derive them. We also discuss the presence or absence of Ha emission with respect to the theory of centrifugally-supported magnetospheres.

  • 7. Alentiev, D.
    et al.
    Kochukhov, Oleg
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Ryabchikova, T.
    Cunha, M.
    Tsymbal, V.
    Weiss, W.
    Discovery of the longest period rapidly oscillating Ap star HD1777652012Inngår i: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 421, nr 1, s. L82-L86Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present the discovery of a long-period, rapidly oscillating Ap (roAp) star, HD177765. Using high-resolution time-series observations obtained with the Ultraviolet and Visual Echelle Spectrograph at the European Southern Observatory Very Large Telescope, we found radial velocity variations with amplitudes 7-150 ms(-1) and a period of 23.6 min, exceeding that of any previously known roAp star. The largest pulsation amplitudes are observed for Eu III, Ce III and for the narrow core of H alpha. We derived the atmospheric parameters and chemical composition of HD177765, showing this star to be similar to other long-period roAp stars. Comparison with theoretical pulsational models indicates an advanced evolutionary state for HD177765. Abundance analyses of this and other roAp stars suggest a systematic variation with age of the rare-earth line anomalies seen in cool Ap stars.

  • 8.
    Alinder, Simon
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Space Situational Awareness with the Swedish Allsky Meteor Network2019Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis investigates the use of the Swedish Allsky Meteor Network (SAMN) for observing, identifying, and determining the orbits of satellites. The overall goal of this project is to determine the feasibility of using such a network for Space Situational Awareness (SSA) purposes, which requires identification and monitoring of objects in orbit. This thesis is a collaboration with the Swedish Defense Research Agency (FOI) to support their efforts in SSA.

    Within the frame of this project, the author developed software that can take data of observations of an object collected from the all-sky cameras of SAMN and do an Initial Orbit Determination (IOD) of the object. An algorithm that improves the results of the IOD was developed and integrated into the software. The software can also identify the object if it is in a database that the program has access to or, if it could not be identified, make an approximate prediction of when and where the object will be visible again the next time it flies over. A program that analyses the stability of the results of the IOD was also developed. This measures the spread in results of the IOD when a small amount of artificial noise is added to one or more of the observed coordinates in the sky. It was found that using multiple cameras at different locations greatly improves the stability of the solutions.

    Gauss' method was used for doing the IODs. The advantages and disadvantages of using this method are discussed, and ultimately other methods, such as the Gooding method or Double R iteration, are recommended for future works. This is mostly because Gauss' method has a singularity when all three lines of sight from observer to object lie in the same plane, which makes the results unreliable.

    The software was tested on a number of observations, both synthetic and real, and the results were compared against known data from public databases. It was found that these techniques can, with some changes, be used for doing IOD and satellite identification, but that doing very accurate position determination required for full orbit determination is not feasible.

  • 9.
    Amarsi, A. M.
    et al.
    Australian Natl Univ, Res Sch Astron & Astrophys, Canberra, ACT 2611, Australia..
    Lind, Karin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik. Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany..
    Asplund, M.
    Australian Natl Univ, Res Sch Astron & Astrophys, Canberra, ACT 2611, Australia..
    Barklem, Paul S.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Teoretisk astrofysik.
    Collet, R.
    Aarhus Univ, Dept Phys & Astron, Stellar Astrophys Ctr, Ny Munkegade 120, DK-8000 Aarhus C, Denmark..
    Non-LTE line formation of Fe in late-type stars - III. 3D non-LTE analysis of metal-poor stars2016Inngår i: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 463, nr 2, s. 1518-1533Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    As one of the most important elements in astronomy, iron abundance determinations need to be as accurate as possible. We investigate the accuracy of spectroscopic iron abundance analyses using archetypal metal-poor stars. We perform detailed 3D non-LTE radiative transfer calculations based on 3D hydrodynamic STAGGER model atmospheres, and employ a new model atom that includes new quantum-mechanical neutral hydrogen collisional rate coefficients. With the exception of the red giant HD122563, we find that the 3D non-LTE models achieve Fe I/Fe II excitation and ionization balance as well as not having any trends with equivalent width to within modelling uncertainties of 0.05 dex, all without having to invoke any microturbulent broadening; for HD122563 we predict that the current best parallax-based surface gravity is overestimated by 0.5 dex. Using a 3D non-LTE analysis, we infer iron abundances from the 3D model atmospheres that are roughly 0.1 dex higher than corresponding abundances from 1D MARCS model atmospheres; these differences go in the same direction as the non-LTE effects themselves. We make available grids of departure coefficients, equivalent widths and abundance corrections, calculated on 1D MARCS model atmospheres and horizontally and temporally averaged 3D STAGGER model atmospheres.

  • 10.
    Amarsi, A. M.
    et al.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany.
    Nissen, P. E.
    Aarhus Univ, Dept Phys & Astron, Stellar Astrophys Ctr, Ny Munkegade 120, DK-8000 Aarhus C, Denmark.
    Asplund, M.
    Australian Natl Univ, Res Sch Astron & Astrophys, Canberra, ACT 2611, Australia;ASTRO 3D, ARC Ctr Excellence All Sky Astrophys 3 Dimens, Sydney, NSW, Australia.
    Lind, Karin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik. Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany.
    Barklem, Paul
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Carbon and oxygen in metal-poor halo stars2019Inngår i: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 622, artikkel-id L4Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Carbon and oxygen are key tracers of the Galactic chemical evolution; in particular, a reported upturn in [C/O] towards decreasing [O/H] in metal-poor halo stars could be a signature of nucleosynthesis by massive Population III stars. We reanalyse carbon, oxygen, and iron abundances in 39 metal-poor turn-off stars. For the first time, we take into account 3D hydrodynamic effects together with departures from local thermodynamic equilibrium (LTE) when determining both the stellar parameters and the elemental abundances, by deriving effective temperatures from 3D non-LTE H beta profiles, surface gravities from Gaia parallaxes, iron abundances from 3D LTE Fe ii equivalent widths, and carbon and oxygen abundances from 3D non-LTE C-I and O-I equivalent widths. We find that [C/Fe] stays flat with [Fe/H], whereas [O/Fe] increases linearly up to 0.75 dex with decreasing [Fe/H] down to -3.0 dex. Therefore [C/O] monotonically decreases towards decreasing [C/H], in contrast to previous findings, mainly because the non-LTE e ff ects for O i at low [Fe/H] are weaker with our improved calculations.

  • 11.
    Andrae, Rene
    et al.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany.
    Fouesneau, Morgan
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany.
    Creevey, Orlagh
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Ordenovic, Christophe
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Mary, Nicolas
    Thales Serv, 290 Allee Lac, F-31670 Labege, France.
    Burlacu, Alexandru
    Telespazio France, 26 Ave Jean Francois Champollion, F-31100 Toulouse, France.
    Chaoul, Laurence
    Ctr Natl Etud Spatiales, 18 Ave Edouard Belin, F-31401 Toulouse, France.
    Jean-Antoine-Piccolo, Anne
    Ctr Natl Etud Spatiales, 18 Ave Edouard Belin, F-31401 Toulouse, France.
    Kordopatis, Georges
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Korn, Andreas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Teoretisk astrofysik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Lebreton, Yveline
    Univ Rennes 1, Inst Phys Rennes, CNRS, UMR 6251, F-35042 Rennes, France;Univ Paris Diderot, LESIA, Observ Paris, PSL Res Univ,CNRS,UMR 8109,Univ Pierre & Marie Cu, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Panem, Chantal
    Ctr Natl Etud Spatiales, 18 Ave Edouard Belin, F-31401 Toulouse, France.
    Pichon, Bernard
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Thevenin, Frederic
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Walmsley, Gavin
    Ctr Natl Etud Spatiales, 18 Ave Edouard Belin, F-31401 Toulouse, France.
    Bailer-Jones, Coryn A. L.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany.
    First stellar parameters from Apsis2018Inngår i: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 616, artikkel-id A8Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The second Gaia data release (Gaia DR2) contains, beyond the astrometry, three-band photometry for 1.38 billion sources. One band is the G band, the other two were obtained by integrating the Gaia prism spectra (BP and RP). We have used these three broad photometric bands to infer stellar effective temperatures, T-eff, for all sources brighter than G = 17 mag with T-eff in the range 3000-10 000K (some 161 million sources). Using in addition the parallaxes, we infer the line-of-sight extinction, A(G), and the reddening, E(BP-RP), for 88 million sources. Together with a bolometric correction we derive luminosity and radius for 77 million sources. These quantities as well as their estimated uncertainties are part of Gaia DR2. Here we describe the procedures by which these quantities were obtained, including the underlying assumptions, comparison with literature estimates, and the limitations of our results. Typical accuracies are of order 324K (T-eff), 0.46 mag (A(G)), 0.23 mag (E(BP-RP)), 15% (luminosity), and 10% (radius). Being based on only a small number of observable quantities and limited training data, our results are necessarily subject to some extreme assumptions that can lead to strong systematics in some cases (not included in the aforementioned accuracy estimates). One aspect is the non-negativity contraint of our estimates, in particular extinction, which we discuss. Yet in several regions of parameter space our results show very good performance, for example for red clump stars and solar analogues. Large uncertainties render the extinctions less useful at the individual star level, but they show good performance for ensemble estimates. We identify regimes in which our parameters should and should not be used and we define a "clean" sample. Despite the limitations, this is the largest catalogue of uniformly-inferred stellar parameters to date. More precise and detailed astrophysical parameters based on the full BP/RP spectrophotometry are planned as part of the third Gaia data release.

  • 12.
    Aronson, Erik
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Bladh, S.
    Univ Padua, Dipartimento Fis & Astron Galileo Galilei, Vicolo Osservatorio 3, I-35122 Padua, Italy.
    Höfner, Susanne
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Teoretisk astrofysik.
    Modelling polarized light from dust shells surrounding asymptotic giant branch stars2017Inngår i: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 603, artikkel-id A116Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Context. Winds of asymptotic giant branch (AGB) stars are commonly assumed to be driven by radiative acceleration of dust grains. For M-type AGB stars, the nature of the wind-driving dust species has been a matter of intense debate. A proposed source of the radiation pressure triggering the outflows is photon scattering on Fe-free silicate grains. This wind-driving mechanism requires grain radii of about 0.1-1 micron in order to make the dust particles efficient at scattering radiation around the stellar flux maximum. Grain size is therefore an important parameter for understanding the physics behind the winds of M-type AGB stars. Aims. We seek to investigate the diagnostic potential of scattered polarized light for determining dust grain sizes. Methods. We have developed a new tool for computing synthetic images of scattered light in dust and gas shells around AGB stars, which can be applied to detailed models of dynamical atmospheres and dust-driven winds. Results. We present maps of polarized light using dynamical models computed with the DARWIN code. The synthetic images clearly show that the intensity of the polarized light, the position of the inner edge of the dust shell, and the size of the dust grains near the inner edge are all changing with the luminosity phase. Non-spherical structures in the dust shells can also have an impact on the polarized light. We simulate this effect by combining different pulsation phases into a single 3D structure before computing synthetic images. An asymmetry of the circumstellar envelope can create a net polarization, which can be used as diagnostics for the grain size. The ratio between the size of the scattering particles and the observed wavelength determines at what wavelengths net polarization switches direction. If observed, this can be used to constrain average particle sizes.

  • 13.
    Aronson, Erik
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Piskunov, Nikolai
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Model-independent Exoplanet Transit Spectroscopy2018Inngår i: Astronomical Journal, ISSN 0004-6256, E-ISSN 1538-3881, Vol. 155, nr 5, artikkel-id 208Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We propose a new data analysis method for obtaining transmission spectra of exoplanet atmospheres and brightness variation across the stellar disk from transit observations. The new method is capable of recovering exoplanet atmosphere absorption spectra and stellar specific intensities without relying on theoretical models of stars and planets. We simultaneously fit both stellar specific intensity and planetary radius directly to transit light curves. This allows stellar models to be removed from the data analysis. Furthermore, we use a data quality weighted filtering technique to achieve an optimal trade-off between spectral resolution and reconstruction fidelity homogenizing the signal-to-noise ratio across the wavelength range. Such an approach is more efficient than conventional data binning onto a low-resolution wavelength grid. We demonstrate that our analysis is capable of reproducing results achieved by using an explicit quadratic limb-darkening equation and that the filtering technique helps eliminate spurious spectral features in regions with strong telluric absorption. The method is applied to the VLT FORS2 observations of the exoplanets GJ 1214 b and WASP-49 b, and our results are in agreement with previous studies. Comparisons between obtained stellar specific intensity and numerical models indicates that the method is capable of accurately reconstructing the specific intensity. The proposed method enables more robust characterization of exoplanetary atmospheres by separating derivation of planetary transmission and stellar specific intensity spectra (that is model-independent) from chemical and physical interpretation.

  • 14.
    Aronson, Erik
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Waldén, P.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Piskunov, Nikolai
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Using near-infrared spectroscopy for characterization of transiting exoplanets2015Inngår i: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 578, artikkel-id A133Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Context. We propose a method for observing transiting exoplanets with near-infrared high-resolution spectrometers. Aims. We aim to create a robust data analysis method for recovering atmospheric transmission spectra from transiting exoplanets over a wide wavelength range in the near-infrared. Methods. By using an inverse method approach, combined with stellar models and telluric transmission spectra, the method recovers the transiting exoplanet's atmospheric transmittance at high precision over a wide wavelength range. We describe our method and have tested it by simulating observations. Results. This method is capable of recovering transmission spectra of high enough accuracy to identify absorption features from molecules such as O-2, CH4, CO2, and H2O. This accuracy is achievable for Jupiter-size exoplanets at S/N that can be reached for 8m class telescopes using high-resolution spectrometers (R > 20 000) during a single transit, and for Earth-size planets and super-Earths transiting late K or M dwarf stars at S/N reachable during observations of less than 10 transits. We also analyse potential error sources to show the robustness of the method. Conclusions. Detection and characterization of atmospheres of both Jupiter-size planets and smaller rocky planets looks promising using this set-up.

  • 15.
    Asadi, Saghar
    et al.
    Stockholm Univ, Oscar Klein Ctr, Dept Astron, AlbaNova, SE-10691 Stockholm, Sweden..
    Zackrisson, Erik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Freeland, Emily
    Stockholm Univ, Oscar Klein Ctr, Dept Astron, AlbaNova, SE-10691 Stockholm, Sweden..
    Probing cold dark matter subhaloes with simulated ALMA observations of macrolensed sub-mm galaxies2017Inngår i: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 472, nr 1, s. 129-140Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    If the dark matter haloes of galaxies contain large numbers of subhaloes as predicted by the Lambda cold dark matter model, these subhaloes are expected to appear in strong galaxy-galaxy lens systems as small-scale perturbations in individual images. We simulate observations of multiply lensed sub-mm galaxies at z similar to 2 as a probe of the dark matter halo of a lens galaxy at z similar to 0.5. We present detection limits for dark substructures based on a visibility plane analysis of simulated Atacama Large Millimeter/submillimeter Array (ALMA) data in bands 7, 8 and 9. We explore two effects: local surface brightness anomalies on angular scales similar to the Einstein radius and the astrometric shift of macroimages. This improves the sensitivity of our lens modelling to the mass of the lens perturber. We investigate the sensitivity of the detection of low-mass subhaloes to the projected position of the subhalo on the image plane as well as the source structure and inner density profile of the lens. We demonstrate that, using the most extended ALMA configuration, pseudo-Jaffe subhaloes can be detected with 99 per cent confidence down to M = 10(7)M(circle dot) . We show how the detection threshold for the three ALMA bands depends on the projected position of the subhalo with respect to the lensed images and conclude that, despite the highest nominal angular resolution, band 9 provides the poorest sensitivity due to observational noise. All simulations use the ALMA Full ops most extended ALMA configuration setup in CASA.

  • 16.
    Babusiaux, C.
    et al.
    Univ Grenoble Alpes, CNRS, IPAG, F-38000 Grenoble, France;Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    van Leeuwen, F.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Barstow, M. A.
    Univ Leicester, Dept Phys & Astron, Leicester Inst Space & Earth Observat, Univ Rd, Leicester LE1 7RH, Leics, England.
    Jordi, C.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Vallenari, A.
    INAF Osservatorio Astron Padova, Vicolo Osservatorio 5, I-35122 Padua, Italy.
    Bossini, D.
    INAF Osservatorio Astron Padova, Vicolo Osservatorio 5, I-35122 Padua, Italy.
    Bressan, A.
    SISSA, Via Bonomea 265, I-34136 Trieste, Italy.
    Cantat-Gaudin, T.
    INAF Osservatorio Astron Padova, Vicolo Osservatorio 5, I-35122 Padua, Italy;Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    van Leeuwen, M.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Brown, A. G. A.
    Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands.
    Prusti, T.
    ESA ESTEC, Directorate Sci, Sci Support Off, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands.
    de Bruijne, J. H. J.
    ESA ESTEC, Directorate Sci, Sci Support Off, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands.
    Bailer-Jones, C. A. L.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany.
    Biermann, M.
    Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany.
    Evans, D. W.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Eyer, L.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland.
    Jansen, F.
    ESA ESTEC, Directorate Sci, Operat Dept, Miss Operat Div, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands.
    Klioner, S. A.
    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany.
    Lammers, U.
    ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Lindegren, L.
    Lund Univ, Dept Astron & Theoret Phys, Lund Observ, Box 43, S-22100 Lund, Sweden.
    Luri, X.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Mignard, F.
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Panem, C.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Pourbaix, D.
    Univ Libre Bruxelles, Inst Astron & Astrophys, CP 226,Blvd Triomphe, B-1050 Brussels, Belgium;FRS FNRS, Rue Egmont 5, B-1000 Brussels, Belgium.
    Randich, S.
    INAF Osservatorio Astrofis Arcetri, Largo Enrico Fermi 5, I-50125 Florence, Italy.
    Sartoretti, P.
    Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Siddiqui, H. I.
    ESA ESAC, Telespazio Vega UK Ltd, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Soubiran, C.
    Univ Bordeaux, CNRS, Lab Astrophys Bordeaux, B18N,Allee Geoffroy St Hilaire, F-33615 Pessac, France.
    Walton, N. A.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Arenou, F.
    Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Bastian, U.
    Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany.
    Cropper, M.
    Univ Coll London, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England.
    Drimmel, R.
    INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Katz, D.
    Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Lattanzi, M. G.
    INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Bakker, J.
    ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Cacciari, C.
    INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy.
    Castaneda, J.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Chaoul, L.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Cheek, N.
    ESA ESAC, Serco Gest Negocios, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    De Angeli, F.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Fabricius, C.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Guerra, R.
    ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Holl, B.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland.
    Masana, E.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Messineo, R.
    ALTEC SpA, Corso Marche 79, I-10146 Turin, Italy.
    Mowlavi, N.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland.
    Nienartowicz, K.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland.
    Panuzzo, P.
    Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Portell, J.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Riello, M.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Seabroke, G. M.
    Univ Coll London, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England.
    Tanga, P.
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Thevenin, F.
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Gracia-Abril, G.
    ESAC, Gaia DPAC Project Off, Camino Bajo Castillo S-N, Madrid 28692, Spain;Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany.
    Comoretto, G.
    ESA ESAC, Telespazio Vega UK Ltd, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Garcia-Reinaldos, M.
    ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Teyssier, D.
    ESA ESAC, Telespazio Vega UK Ltd, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Altmann, M.
    Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany;Sorbonne Univ, LNE, Univ PSL, Observ Paris,SYRTE,CNRS, 61 Ave Observ, F-75014 Paris, France.
    Andrae, R.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany.
    Audard, M.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland.
    Bellas-Velidis, I.
    Natl Observ Athens I Metaxa & Vas Pavlou Palaia P, Athens 15236, Greece.
    Benson, K.
    Univ Coll London, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England.
    Berthier, J.
    Univ Lille, Sorbonne Univ, Univ PSL, Observ Paris,IMCCE, 77 Av Denfert Rochereau, F-75014 Paris, France.
    Blomme, R.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium.
    Burgess, P.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Busso, G.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Carry, B.
    Univ Lille, Sorbonne Univ, Univ PSL, Observ Paris,IMCCE, 77 Av Denfert Rochereau, F-75014 Paris, France;Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Cellino, A.
    INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Clementini, G.
    INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy.
    Clotet, M.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Creevey, O.
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Davidson, M.
    Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland.
    De Ridder, J.
    Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven, Belgium.
    Delchambre, L.
    Univ Liege, Inst Astrophys & Geophys, 19c Allee 6 Aout, B-4000 Liege, Belgium.
    Dell'Oro, A.
    INAF Osservatorio Astrofis Arcetri, Largo Enrico Fermi 5, I-50125 Florence, Italy.
    Ducourant, C.
    Univ Bordeaux, CNRS, Lab Astrophys Bordeaux, B18N,Allee Geoffroy St Hilaire, F-33615 Pessac, France.
    Fernandez-Hernandez, J.
    ESA ESAC, ATG Europe, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Fouesneau, M.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany.
    Fremat, Y.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium.
    Galluccio, L.
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Garcia-Torres, M.
    Univ Pablo Olavide, Area Lenguajes Sistemas Informat, Ctr Utrera,Km 1, Seville 41013, Spain.
    Gonzalez-Nunez, J.
    ESA ESAC, Serco Gest Negocios, Camino Bajo Castillo S-N, Madrid 28692, Spain;Univ Vigo, ETSE Telecomun, Campus Lagoas Marcosende, Vigo 36310, Spain.
    Gonzalez-Vidal, J. J.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Gosset, E.
    FRS FNRS, Rue Egmont 5, B-1000 Brussels, Belgium;Univ Liege, Inst Astrophys & Geophys, 19c Allee 6 Aout, B-4000 Liege, Belgium.
    Guy, L. P.
    Large Synopt Survey Telescope, 950 N Cherry Ave, Tucson, AZ 85719 USA;Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland.
    Halbwachs, J. -L
    Hambly, N. C.
    Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland.
    Harrison, D. L.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England;Univ Cambridge, Kavli Inst Cosmol, Madingley Rd, Cambride CB3 0HA, England.
    Hernandez, J.
    ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Hestroffer, D.
    Univ Lille, Sorbonne Univ, Univ PSL, Observ Paris,IMCCE, 77 Av Denfert Rochereau, F-75014 Paris, France.
    Hodgkin, S. T.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Hutton, A.
    ESA ESAC, Aurora Technol, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Jasniewicz, G.
    Univ Montpellier, Lab Univ & Particules Montpellier, Pl Eugene Bataillon,CC72, F-34095 Montpellier 05, France.
    Jean-Antoine-Piccolo, A.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Jordan, S.
    Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany.
    Korn, Andreas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Teoretisk astrofysik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Krone-Martins, A.
    Univ Lisbon, CENTRA, FCUL, Campo Grande,Edif C8, P-1749016 Lisbon, Portugal.
    Lanzafame, A. C.
    Univ Catania, Dipartimento Fis & Astron, Sez Astrofis, Via S Sofia 78, I-95123 Catania, Italy;INAF, Osservatorio Astrofis Catania, Via S Sofia 78, I-95123 Catania, Italy.
    Lebzelter, T.
    Univ Vienna, Dept Astrophys, Turkenschanzstr 17, A-1180 Vienna, Austria.
    Loeffler, W.
    Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany.
    Manteiga, M.
    Univ A Coruna, CITIC Astron & Astrophys, Campus Elvina S-N, La Coruna 15071, Spain;Univ A Coruna, CITIC, Dept Comp Sci, Campus Elvina S-N, La Coruna 15071, Spain.
    Marrese, P. M.
    INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Monte Porzio Catone, Italy;ASI, Space Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy.
    Martin-Fleitas, J. M.
    ESA ESAC, Aurora Technol, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Moitinho, A.
    Univ Lisbon, CENTRA, FCUL, Campo Grande,Edif C8, P-1749016 Lisbon, Portugal.
    Mora, A.
    ESA ESAC, Aurora Technol, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Muinonen, K.
    Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland;Finnish Geospatial Res Inst FGI, Geodeetinrinne 2, Masala 02430, Finland.
    Osinde, J.
    ESA ESAC, Isdefe, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Pancino, E.
    ASI, Space Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy;INAF Osservatorio Astrofis Arcetri, Largo Enrico Fermi 5, I-50125 Florence, Italy.
    Pauwels, T.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium.
    Petit, J. -M
    Recio-Blanco, A.
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Richards, P. J.
    Rutherford Appleton Lab, STFC, Harwell OX11 0QX, Didcot, England.
    Rimoldini, L.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland.
    Robin, A. C.
    Univ Bourgogne Franche Comte, Inst UTINAM UMR6213, CNRS, OSU THETA Franche Comte Bourgogne, F-25000 Besancon, France.
    Sarro, L. M.
    UNED, Dept Inteligencia Artificial, C Juan Rosal 16, Madrid 28040, Spain.
    Siopis, C.
    Univ Libre Bruxelles, Inst Astron & Astrophys, CP 226,Blvd Triomphe, B-1050 Brussels, Belgium.
    Smith, M.
    Univ Coll London, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England.
    Sozzetti, A.
    INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Sueveges, M.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany.
    Torra, J.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    van Reeven, W.
    ESA ESAC, Aurora Technol, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Abbas, U.
    INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Abreu Aramburu, A.
    ESA ESAC, Elecnor Deimos Space, Camino Bajo Castillo S-N, Madrid 28692, Spain;Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany;INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy;Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain;Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland;Univ Liege, Inst Astrophys & Geophys, 19c Allee 6 Aout, B-4000 Liege, Belgium.
    Accart, S.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Aerts, C.
    Radboud Univ Nijmegen, Dept Astrophys, IMAPP, POB 9010, NL-6500 GL Nijmegen, Netherlands;Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven, Belgium.
    Altavilla, G.
    INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Monte Porzio Catone, Italy;ASI, Space Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy;INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy.
    Alvarez, M. A.
    Univ A Coruna, CITIC, Dept Comp Sci, Campus Elvina S-N, La Coruna 15071, Spain.
    Alvarez, R.
    ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Alves, J.
    Univ Vienna, Dept Astrophys, Turkenschanzstr 17, A-1180 Vienna, Austria.
    Anderson, R. I.
    European Southern Observ, Karl Schwarzschild Str 2, D-85748 Garching, Germany;Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland.
    Andrei, A. H.
    Sorbonne Univ, LNE, Univ PSL, Observ Paris,SYRTE,CNRS, 61 Ave Observ, F-75014 Paris, France;ON MCTI BR, Rua Gal Jose Cristino 77, BR-20921400 Rio De Janeiro, Brazil;OV UFRJ BR, Ladeira Pedro Antonio 43, BR-20080090 Rio De Janeiro, Brazil.
    Anglada Varela, E.
    ESA ESAC, ATG Europe, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Antiche, E.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Antoja, T.
    ESA ESTEC, Directorate Sci, Sci Support Off, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands;Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Arcay, B.
    Univ A Coruna, CITIC, Dept Comp Sci, Campus Elvina S-N, La Coruna 15071, Spain.
    Astraatmadja, T. L.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany;Carnegie Inst Sci, Dept Terr Magnetism, 5241 Broad Branch Rd,NW, Washington, DC 20015 USA.
    Bach, N.
    ESA ESAC, Aurora Technol, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Baker, S. G.
    Univ Coll London, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England.
    Balaguer-Nunez, L.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Balm, P.
    ESA ESAC, Telespazio Vega UK Ltd, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Barache, C.
    Sorbonne Univ, LNE, Univ PSL, Observ Paris,SYRTE,CNRS, 61 Ave Observ, F-75014 Paris, France.
    Barata, C.
    Univ Lisbon, CENTRA, FCUL, Campo Grande,Edif C8, P-1749016 Lisbon, Portugal.
    Barbato, D.
    Univ Torino, Dipartimento Fis, Via Pietro Giuria 1, I-10125 Turin, Italy;INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Barblan, F.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland.
    Barklem, Paul
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Teoretisk astrofysik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Barrado, D.
    ESA ESAC, Dept Astrofis, Ctr Astrobiol, CSIC INTA, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Barros, M.
    Univ Lisbon, CENTRA, FCUL, Campo Grande,Edif C8, P-1749016 Lisbon, Portugal.
    Bartholome Munoz, S.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Bassilana, J. -L
    Becciani, U.
    INAF, Osservatorio Astrofis Catania, Via S Sofia 78, I-95123 Catania, Italy.
    Bellazzini, M.
    INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy.
    Berihuete, A.
    Univ Cadiz, Dept Estadist, Calle Republica Arabe Saharawi S-N, Puerto Real 11510, Spain;Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany;Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Bertones, S.
    Sorbonne Univ, LNE, Univ PSL, Observ Paris,SYRTE,CNRS, 61 Ave Observ, F-75014 Paris, France;INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy;Bern Univ, Astron Inst, Sidlerstr 5, CH-3012 Bern, Switzerland.
    Bianchi, L.
    EURIX Srl, Corso Vittorio Emanuele 2 61, I-10128 Turin, Italy.
    Bienayme, O.
    Univ Strasbourg, CNRS, Observ Astron Strasbourg, UMR 7550, 11 Rue Univ, F-67000 Strasbourg, France.
    Blanco-Cuaresma, S.
    Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA;Univ Bordeaux, CNRS, Lab Astrophys Bordeaux, B18N,Allee Geoffroy St Hilaire, F-33615 Pessac, France;Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland.
    Boch, T.
    Univ Strasbourg, CNRS, Observ Astron Strasbourg, UMR 7550, 11 Rue Univ, F-67000 Strasbourg, France.
    Boeche, C.
    INAF Osservatorio Astron Padova, Vicolo Osservatorio 5, I-35122 Padua, Italy.
    Bombrun, A.
    ESA ESAC, HE Space Operat BV, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Borrachero, R.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Bouquillon, S.
    Sorbonne Univ, LNE, Univ PSL, Observ Paris,SYRTE,CNRS, 61 Ave Observ, F-75014 Paris, France.
    Bourda, G.
    Univ Bordeaux, CNRS, Lab Astrophys Bordeaux, B18N,Allee Geoffroy St Hilaire, F-33615 Pessac, France.
    Bragaglia, A.
    INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy.
    Bramante, L.
    ALTEC SpA, Corso Marche 79, I-10146 Turin, Italy.
    Breddels, M. A.
    Univ Groningen, Kapteyn Astron Inst, Landleven 12, NL-9747 AD Groningen, Netherlands.
    Brouillet, N.
    Univ Bordeaux, CNRS, Lab Astrophys Bordeaux, B18N,Allee Geoffroy St Hilaire, F-33615 Pessac, France.
    Bruesemeister, T.
    Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany.
    Brugaletta, E.
    INAF, Osservatorio Astrofis Catania, Via S Sofia 78, I-95123 Catania, Italy.
    Bucciarelli, B.
    INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Burlacu, A.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Busonero, D.
    INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Butkevich, A. G.
    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany.
    Buzzi, R.
    INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Caffau, E.
    Cancelliere, R.
    Univ Turin, Dept Comp Sci, Corso Svizzera 185, I-10149 Turin, Italy.
    Cannizzaro, G.
    Radboud Univ Nijmegen, Dept Astrophys, IMAPP, POB 9010, NL-6500 GL Nijmegen, Netherlands;SRON, Netherlands Inst Space Res, Sorbonnelaan 2, NL-3584CA Utrecht, Netherlands.
    Carballo, R.
    Univ Cantabria, Dept Matemat Aplicada & Ciencias Comp, ETS Ingenieros Caminos Canales & Puertos, Avda Castros S-N, E-39005 Santander, Spain.
    Carlucci, T.
    Sorbonne Univ, LNE, Univ PSL, Observ Paris,SYRTE,CNRS, 61 Ave Observ, F-75014 Paris, France.
    Carrasco, J. M.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Casamiquela, L.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Castellani, M.
    INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Monte Porzio Catone, Italy.
    Castro-Ginard, A.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Charlot, P.
    Univ Bordeaux, CNRS, Lab Astrophys Bordeaux, B18N,Allee Geoffroy St Hilaire, F-33615 Pessac, France.
    Chemin, L.
    Univ Antofagasta, Unidad Astron, Ave Angamos 601, Antofagasta 1270300, Chile.
    Chiavassa, A.
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Cocozza, G.
    INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy.
    Costigan, G.
    Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands.
    Cowell, S.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Crifo, F.
    Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Crosta, M.
    INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Crowley, C.
    ESA ESAC, HE Space Operat BV, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Cuypers, J.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium.
    Dafonte, C.
    Univ A Coruna, CITIC, Dept Comp Sci, Campus Elvina S-N, La Coruna 15071, Spain.
    Damerdji, Y.
    CRAAG, Route Observ Bp 63, Algiers 16340, Algeria;Univ Liege, Inst Astrophys & Geophys, 19c Allee 6 Aout, B-4000 Liege, Belgium.
    Dapergolas, A.
    Natl Observ Athens I Metaxa & Vas Pavlou Palaia P, Athens 15236, Greece.
    David, P.
    Univ Lille, Sorbonne Univ, Univ PSL, Observ Paris,IMCCE, 77 Av Denfert Rochereau, F-75014 Paris, France.
    David, M.
    Univ Antwerp, Onderzoeksgroep Toegepaste Wiskunde, Middelheimlaan 1, B-2020 Antwerp, Belgium.
    de laverny, P.
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    De Luise, F.
    INAF, Osservatorio Astron Abruzzo, Via Mentore Maggini, I-64100 Teramo, Italy.
    De March, R.
    ALTEC SpA, Corso Marche 79, I-10146 Turin, Italy.
    de Martino, D.
    INAF, Osservatorio Astron Capodimonte, Via Moiariello 16, I-80131 Naples, Italy.
    de Souza, R.
    Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Rua Matao 1226,Cidade Univ, BR-05508900 Sao Paulo, Brazil.
    de Torres, A.
    ESA ESAC, HE Space Operat BV, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Debosscher, J.
    Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven, Belgium.
    del Pozo, E.
    ESA ESAC, Aurora Technol, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Delbo, M.
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Delgado, A.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Delgado, H. E.
    UNED, Dept Inteligencia Artificial, C Juan Rosal 16, Madrid 28040, Spain.
    Diakite, S.
    Univ Bourgogne Franche Comte, Inst UTINAM UMR6213, CNRS, OSU THETA Franche Comte Bourgogne, F-25000 Besancon, France.
    Diener, C.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Distefano, E.
    INAF, Osservatorio Astrofis Catania, Via S Sofia 78, I-95123 Catania, Italy.
    Dolding, C.
    Univ Coll London, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England.
    Drazinos, P.
    Univ Athens, Dept Astrophys Astron & Mech, Panepistimiopolis, Athens 15783, Greece.
    Duran, J.
    ESA ESAC, Isdefe, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Edvardsson, Bengt
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Teoretisk astrofysik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Enke, H.
    AIP, Leibniz Inst Astrophys Potsdam, Sternwarte 16, D-14482 Potsdam, Germany.
    Eriksson, Kjell
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Teoretisk astrofysik.
    Esquej, P.
    ESA ESAC, RHEA, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Bontemps, G. Eynard
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Fabre, C.
    CNES Ctr Spatial Toulouse, ATOS, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Fabrizio, M.
    INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Monte Porzio Catone, Italy;ASI, Space Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy.
    Faigler, S.
    Tel Aviv Univ, Sch Phys & Astron, IL-6997801 Tel Aviv, Israel.
    Falcao, A. J.
    UNINOVA CTS, Campus FCT UNL, P-2829516 Caparica, Portugal.
    Casas, M. Farras
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Federici, L.
    INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy.
    Fedorets, G.
    Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland.
    Fernique, P.
    Univ Strasbourg, CNRS, Observ Astron Strasbourg, UMR 7550, 11 Rue Univ, F-67000 Strasbourg, France.
    Figueras, F.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Filippi, F.
    ALTEC SpA, Corso Marche 79, I-10146 Turin, Italy.
    Findeisen, K.
    Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Fonti, A.
    ALTEC SpA, Corso Marche 79, I-10146 Turin, Italy.
    Fraile, E.
    ESA ESAC, RHEA, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Fraser, M.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England;Univ Coll Dublin, Sch Phys, OBrien Ctr Sci North, Dublin 4, Ireland.
    Frezouls, B.
    Univ Antwerp, Onderzoeksgroep Toegepaste Wiskunde, Middelheimlaan 1, B-2020 Antwerp, Belgium.
    Gai, M.
    INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Galleti, S.
    INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy.
    Garabato, D.
    Univ A Coruna, CITIC, Dept Comp Sci, Campus Elvina S-N, La Coruna 15071, Spain.
    Garcia-Sedano, F.
    UNED, Dept Inteligencia Artificial, C Juan Rosal 16, Madrid 28040, Spain.
    Garofalo, A.
    Univ Bologna, Dipartimento Fis & Astron, Via Piero Gobetti 93-2, I-40129 Bologna, Italy;INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy.
    Garralda, N.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Gavel, Alvin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Teoretisk astrofysik.
    Gavras, P.
    Univ Athens, Dept Astrophys Astron & Mech, Panepistimiopolis, Athens 15783, Greece;Natl Observ Athens I Metaxa & Vas Pavlou Palaia P, Athens 15236, Greece;Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Gerssen, J.
    AIP, Leibniz Inst Astrophys Potsdam, Sternwarte 16, D-14482 Potsdam, Germany.
    Geyer, R.
    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany.
    Giacobbe, P.
    INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Gilmore, G.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Girona, S.
    Ctr Nacl Super Comp, Barcelona Supercomputing Ctr, C Jordi Girona 29,Ed Nexus 2, Barcelona 08034, Spain.
    Giuffrida, G.
    INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Monte Porzio Catone, Italy;ASI, Space Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy.
    Glass, F.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland.
    Gomes, M.
    Univ Lisbon, CENTRA, FCUL, Campo Grande,Edif C8, P-1749016 Lisbon, Portugal.
    Granvik, M.
    Lulea Univ Technol, Dept Comp Sci Elect & Space Engn, Box 848, S-98128 Kiruna, Sweden;Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland.
    Gueguen, A.
    Max Planck Inst Extraterrestrial Phys, High Energy Grp, Giessenbachstr, D-85741 Garching, Germany;Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Guerrier, A.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Guiraud, J.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Gutierrez-Sanchez, R.
    ESA ESAC, Telespazio Vega UK Ltd, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Haigron, R.
    Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Hatzidimitriou, D.
    Univ Athens, Dept Astrophys Astron & Mech, Panepistimiopolis, Athens 15783, Greece;Natl Observ Athens I Metaxa & Vas Pavlou Palaia P, Athens 15236, Greece.
    Hauser, M.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany;Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany.
    Haywood, M.
    Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Heiter, Ulrike
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Helmi, A.
    Univ Groningen, Kapteyn Astron Inst, Landleven 12, NL-9747 AD Groningen, Netherlands.
    Heu, J.
    Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Hilger, T.
    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany.
    Hobbs, D.
    Lund Univ, Dept Astron & Theoret Phys, Lund Observ, Box 43, S-22100 Lund, Sweden.
    Hofmann, W.
    Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany.
    Holland, G.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Huckle, H. E.
    Univ Coll London, Mullard Space Sci Lab, Holmbury St Mary, Dorking RH5 6NT, Surrey, England.
    Hypki, A.
    Adam Mickiewicz Univ, Astron Observ Inst, Fac Phys, Sloneczna 36, PL-60286 Poznan, Poland;Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands.
    Icardi, V.
    ALTEC SpA, Corso Marche 79, I-10146 Turin, Italy.
    Janssen, K.
    AIP, Leibniz Inst Astrophys Potsdam, Sternwarte 16, D-14482 Potsdam, Germany.
    Jevardat de Fombelle, G.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland.
    Jonker, P. G.
    Radboud Univ Nijmegen, Dept Astrophys, IMAPP, POB 9010, NL-6500 GL Nijmegen, Netherlands;SRON, Netherlands Inst Space Res, Sorbonnelaan 2, NL-3584CA Utrecht, Netherlands.
    Juhasz, A. L.
    Hungarian Acad Sci, Konkoly Observ, Res Ctr Astron & Earth Sci, Konkoly Thege Miklos Ut 15-17, H-1121 Budapest, Hungary;Eotvos Lorand Univ, Egyet Ter 1-3, H-1053 Budapest, Hungary.
    Julbe, F.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Karampelas, A.
    Amer Community Sch Athens, 129 Aghias Paraskevis Ave & Kazantzaki St, Athens 15234, Greece;Univ Athens, Dept Astrophys Astron & Mech, Panepistimiopolis, Athens 15783, Greece.
    Kewley, A.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Klar, J.
    AIP, Leibniz Inst Astrophys Potsdam, Sternwarte 16, D-14482 Potsdam, Germany.
    Kochoska, A.
    Univ Ljubljana, Fac Math & Phys, Jadranska Ulica 19, Ljubljana 1000, Slovenia;Villanova Univ, Dept Astrophys & Planetary Sci, 800 Lancaster Ave, Villanova, PA 19085 USA.
    Kohley, R.
    ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Kolenberg, K.
    Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven, Belgium;Univ Antwerp, Phys Dept, Groenenborgerlaan 171, B-2020 Antwerp, Belgium;Harvard Smithsonian Ctr Astrophys, 60 Garden St, Cambridge, MA 02138 USA.
    Kontizas, M.
    Univ Athens, Dept Astrophys Astron & Mech, Panepistimiopolis, Athens 15783, Greece.
    Kontizas, E.
    Natl Observ Athens I Metaxa & Vas Pavlou Palaia P, Athens 15236, Greece.
    Koposov, S. E.
    Carnegie Mellon Univ, McWilliams Ctr Cosmol, Dept Phys, 5000 Forbes Ave, Pittsburgh, PA 15213 USA;Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Kordopatis, G.
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Kostrzewa-Rutkowska, Z.
    Radboud Univ Nijmegen, Dept Astrophys, IMAPP, POB 9010, NL-6500 GL Nijmegen, Netherlands;SRON, Netherlands Inst Space Res, Sorbonnelaan 2, NL-3584CA Utrecht, Netherlands.
    Koubsky, P.
    Acad Sci Czech Republ, Astron Inst, Fricova 298, Ondrejov 25165, Czech Republic.
    Lambert, S.
    Sorbonne Univ, LNE, Univ PSL, Observ Paris,SYRTE,CNRS, 61 Ave Observ, F-75014 Paris, France.
    Lanza, A. F.
    INAF, Osservatorio Astrofis Catania, Via S Sofia 78, I-95123 Catania, Italy.
    Lasne, Y.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Lavigne, J. -B
    Le Fustec, Y.
    CNES Ctr Spatial Toulouse, Telespazio, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Le Poncin-Lafitte, C.
    Sorbonne Univ, LNE, Univ PSL, Observ Paris,SYRTE,CNRS, 61 Ave Observ, F-75014 Paris, France.
    Lebreton, Y.
    Univ Rennes 1, Inst Phys Rennes, F-35042 Rennes, France;Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Leccia, S.
    INAF, Osservatorio Astron Capodimonte, Via Moiariello 16, I-80131 Naples, Italy.
    Leclerc, N.
    Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Lecoeur-Taibi, I.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland.
    Lenhardt, H.
    Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany.
    Leroux, F.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Liao, S.
    Chinese Acad Sci, Shanghai Astron Observ, 80 Nandan Rd, Shanghai 200030, Peoples R China;INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy;Univ Chinese Acad Sci, Sch Astron & Space Sci, Beijing 100049, Peoples R China.
    Licata, E.
    EURIX Srl, Corso Vittorio Emanuele 2 61, I-10128 Turin, Italy.
    Lindstrom, H. E. P.
    Univ Copenhagen, Niels Bohr Inst, Juliane Maries Vej 30, DK-2100 Copenhagen, Denmark;DXC Technol, Retortvej 8, DK-2500 Valby, Denmark.
    Lister, T. A.
    Las Cumbres Observ, 6740 Cortona Dr Suite, Goleta, CA 93117 USA.
    Livanou, E.
    Univ Athens, Dept Astrophys Astron & Mech, Panepistimiopolis, Athens 15783, Greece.
    Lobel, A.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium.
    Lopez, M.
    ESA ESAC, Dept Astrofis, Ctr Astrobiol, CSIC INTA, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Managau, S.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Mann, R. G.
    Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland.
    Mantelet, G.
    Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany.
    Marchal, O.
    Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Marchant, J. M.
    Liverpool John Moores Univ, Astrophys Res Inst, 146 Brownlow Hill, Liverpool L3 5RF, Merseyside, England.
    Marconi, M.
    INAF, Osservatorio Astron Capodimonte, Via Moiariello 16, I-80131 Naples, Italy.
    Marinoni, S.
    INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Monte Porzio Catone, Italy;ASI, Space Sci Data Ctr, Via Politecn SNC, I-00133 Rome, Italy.
    Marschalko, G.
    Hungarian Acad Sci, Konkoly Observ, Res Ctr Astron & Earth Sci, Konkoly Thege Miklos Ut 15-17, H-1121 Budapest, Hungary;Univ Szeged, Baja Observ, Szegedi Ut II 70, H-6500 Baja, Hungary.
    Marshall, D. J.
    Univ Paris Diderot, Lab AIM, IRFU Serv Astrophys, CEA DSM CNRS, Bat 709,CEA Saclay, F-91191 Gif Sur Yvette, France.
    Martino, M.
    ALTEC SpA, Corso Marche 79, I-10146 Turin, Italy.
    Marton, G.
    Hungarian Acad Sci, Konkoly Observ, Res Ctr Astron & Earth Sci, Konkoly Thege Miklos Ut 15-17, H-1121 Budapest, Hungary.
    Mary, N.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Massari, D.
    Univ Groningen, Kapteyn Astron Inst, Landleven 12, NL-9747 AD Groningen, Netherlands.
    Matijevic, G.
    AIP, Leibniz Inst Astrophys Potsdam, Sternwarte 16, D-14482 Potsdam, Germany.
    Mazeh, T.
    Tel Aviv Univ, Sch Phys & Astron, IL-6997801 Tel Aviv, Israel.
    McMillan, P. J.
    Lund Univ, Dept Astron & Theoret Phys, Lund Observ, Box 43, S-22100 Lund, Sweden.
    Messina, S.
    INAF, Osservatorio Astrofis Catania, Via S Sofia 78, I-95123 Catania, Italy.
    Michalik, D.
    Lund Univ, Dept Astron & Theoret Phys, Lund Observ, Box 43, S-22100 Lund, Sweden.
    Millar, N. R.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Molina, D.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Molinaro, R.
    INAF, Osservatorio Astron Capodimonte, Via Moiariello 16, I-80131 Naples, Italy.
    Molnar, L.
    Hungarian Acad Sci, Konkoly Observ, Res Ctr Astron & Earth Sci, Konkoly Thege Miklos Ut 15-17, H-1121 Budapest, Hungary.
    Montegriffo, P.
    INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy.
    Mor, R.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Morbidelli, R.
    INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Morel, T.
    Univ Liege, Inst Astrophys & Geophys, 19c Allee 6 Aout, B-4000 Liege, Belgium.
    Morris, D.
    Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland.
    Mulone, A. F.
    ALTEC SpA, Corso Marche 79, I-10146 Turin, Italy.
    Muraveva, T.
    Musella, I.
    INAF, Osservatorio Astron Capodimonte, Via Moiariello 16, I-80131 Naples, Italy.
    Nelemans, G.
    Radboud Univ Nijmegen, Dept Astrophys, IMAPP, POB 9010, NL-6500 GL Nijmegen, Netherlands;Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven, Belgium.
    Nicastro, L.
    INAF, Osservatorio Astrofis & Sci Spazio Bologna, Via Piero Gobetti 93-3, I-40129 Bologna, Italy.
    Noval, L.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    O'Mullane, W.
    Large Synopt Survey Telescope, 950 N Cherry Ave, Tucson, AZ 85719 USA;ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Ordenovic, C.
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Ordonez-Blanco, D.
    Univ Geneva, Dept Astron, Chemin Ecogia 16, CH-1290 Versoix, Switzerland.
    Osborne, P.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Pagani, C.
    Univ Leicester, Dept Phys & Astron, Leicester Inst Space & Earth Observat, Univ Rd, Leicester LE1 7RH, Leics, England.
    Pagano, I.
    INAF, Osservatorio Astrofis Catania, Via S Sofia 78, I-95123 Catania, Italy.
    Pailler, F.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Palacin, H.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Palaversa, L.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England;Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland.
    Panahi, A.
    Tel Aviv Univ, Sch Phys & Astron, IL-6997801 Tel Aviv, Israel.
    Pawlak, M.
    Univ Warsaw Observ, Al Ujazdowskie 4, PL-00478 Warsaw, Poland;Charles Univ Prague, Inst Theoret Phys, Fac Math & Phys, Prague, Czech Republic.
    Piersimoni, A. M.
    INAF, Osservatorio Astron Abruzzo, Via Mentore Maggini, I-64100 Teramo, Italy.
    Pineau, F. -X
    Plachy, E.
    Hungarian Acad Sci, Konkoly Observ, Res Ctr Astron & Earth Sci, Konkoly Thege Miklos Ut 15-17, H-1121 Budapest, Hungary.
    Plum, G.
    Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Poggio, E.
    Univ Torino, Dipartimento Fis, Via Pietro Giuria 1, I-10125 Turin, Italy;INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Poujoulet, E.
    CNES Ctr Spatial Toulouse, AKKA, 18 Ave Edouard Belin, F-31401 Toulouse 9, France;ESA ESTEC, HE Space Operat BV, Keplerlaan 1, NL-2201 AZ Noordwijk, Netherlands.
    Prsa, A.
    Villanova Univ, Dept Astrophys & Planetary Sci, 800 Lancaster Ave, Villanova, PA 19085 USA.
    Pulone, L.
    INAF, Osservatorio Astron Roma, Via Frascati 33, I-00078 Monte Porzio Catone, Italy.
    Racero, E.
    ESA ESAC, Serco Gest Negocios, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Ragaini, S.
    Rambaux, N.
    Univ Lille, Sorbonne Univ, Univ PSL, Observ Paris,IMCCE, 77 Av Denfert Rochereau, F-75014 Paris, France.
    Ramos-Lerate, M.
    ESA ESAC, Vitrociset Belgium, Camino Bajo Castillo S-N, Madrid 28692, Spain;Space Telescope Sci Inst, 3700 San Martin Dr, Baltimore, MD 21218 USA.
    Regibo, S.
    Katholieke Univ Leuven, Inst Sterrenkunde, Celestijnenlaan 200D, B-3001 Leuven, Belgium.
    Reyle, C.
    Univ Bourgogne Franche Comte, Inst UTINAM UMR6213, CNRS, OSU THETA Franche Comte Bourgogne, F-25000 Besancon, France.
    Riclet, F.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Ripepi, V.
    INAF, Osservatorio Astron Capodimonte, Via Moiariello 16, I-80131 Naples, Italy.
    Riva, A.
    INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Rivard, A.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Rixon, G.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Roegiers, T.
    ESA ESAC, QUASAR Sci Resources, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Roelens, M.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland.
    Romero-Gomez, M.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Rowell, N.
    Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland.
    Royer, F.
    Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Ruiz-Dern, L.
    Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Sadowski, G.
    Univ Libre Bruxelles, Inst Astron & Astrophys, CP 226,Blvd Triomphe, B-1050 Brussels, Belgium.
    Sagrista Selles, T.
    Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany.
    Sahlmann, J.
    Fork Res, Rua Cruzado Osberno,Lt 1,9 Esq, Lisbon, Portugal;ESA ESAC, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Salgado, J.
    CNES Ctr Spatial Toulouse, APAVE SUDEUROPE SAS, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Salguero, E.
    ESA ESAC, ATG Europe, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Sanna, N.
    INAF Osservatorio Astrofis Arcetri, Largo Enrico Fermi 5, I-50125 Florence, Italy.
    Santana-Ros, T.
    Adam Mickiewicz Univ, Astron Observ Inst, Fac Phys, Sloneczna 36, PL-60286 Poznan, Poland.
    Sarasso, M.
    INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Savietto, H.
    Nord Optic Telescope, Rambla Jose Ana Fernandez Perez 7, Brena Baja 38711, Spain.
    Schultheis, M.
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Sciacca, E.
    INAF, Osservatorio Astrofis Catania, Via S Sofia 78, I-95123 Catania, Italy.
    Segol, M.
    Spanish Virtual Observ, Santander, Spain.
    Segovia, J. C.
    ESA ESAC, Serco Gest Negocios, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Segransan, D.
    Univ Geneva, Dept Astron, Chemin Maillettes 51, CH-1290 Versoix, Switzerland.
    Shih, I-C
    Siltala, L.
    INAF, Fdn Galileo Galilei, Rambla Jose Ana Fernandez Perez 7, Brena Baja 38712, Santa Cruz Tene, Spain;Univ Helsinki, Dept Phys, FIN-00014 Helsinki, Finland.
    Silva, A. F.
    Univ Lisbon, CENTRA, FCUL, Campo Grande,Edif C8, P-1749016 Lisbon, Portugal.
    Smart, R. L.
    INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Smith, K. W.
    Max Planck Inst Astron, Konigstuhl 17, D-69117 Heidelberg, Germany.
    Solano, E.
    ESA ESAC, Dept Astrofis, Ctr Astrobiol, CSIC INTA, Camino Bajo Castillo S-N, Madrid 28692, Spain;ESA ESAC, INSA, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Solitro, F.
    ALTEC SpA, Corso Marche 79, I-10146 Turin, Italy.
    Sordo, R.
    INAF Osservatorio Astron Padova, Vicolo Osservatorio 5, I-35122 Padua, Italy.
    Soria Nieto, S.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Souchay, J.
    Sorbonne Univ, LNE, Univ PSL, Observ Paris,SYRTE,CNRS, 61 Ave Observ, F-75014 Paris, France.
    Spagna, A.
    INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Spoto, F.
    Univ Lille, Sorbonne Univ, Univ PSL, Observ Paris,IMCCE, 77 Av Denfert Rochereau, F-75014 Paris, France;Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Stampa, U.
    Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany.
    Steele, I. A.
    Liverpool John Moores Univ, Astrophys Res Inst, 146 Brownlow Hill, Liverpool L3 5RF, Merseyside, England.
    Steidelmueller, H.
    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany.
    Stephenson, C. A.
    ESA ESAC, Telespazio Vega UK Ltd, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Stoev, H.
    Univ Complutense Madrid, Dept Arquitectura Computadores & Automat, Fac Informat, C Prof Jose Garcia Santesmases S-N, E-28040 Madrid, Spain.
    Suess, F. F.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Surdej, J.
    Univ Liege, Inst Astrophys & Geophys, 19c Allee 6 Aout, B-4000 Liege, Belgium.
    Szabados, L.
    Hungarian Acad Sci, Konkoly Observ, Res Ctr Astron & Earth Sci, Konkoly Thege Miklos Ut 15-17, H-1121 Budapest, Hungary.
    Szegedi-Elek, E.
    Hungarian Acad Sci, Konkoly Observ, Res Ctr Astron & Earth Sci, Konkoly Thege Miklos Ut 15-17, H-1121 Budapest, Hungary.
    Tapiador, D.
    Univ Bristol, HH Wills Phys Lab, Tyndall Ave, Bristol BS8, Avon, England;IEEC, Gran Capita 2-4,08034, Bristol BS8 1TL, Avon, England.
    Taris, F.
    Sorbonne Univ, LNE, Univ PSL, Observ Paris,SYRTE,CNRS, 61 Ave Observ, F-75014 Paris, France.
    Tauran, G.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Taylor, M. B.
    Univ Vigo, Appl Phys Dept, Vigo 36310, Spain.
    Teixeira, R.
    Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Rua Matao 1226,Cidade Univ, BR-05508900 Sao Paulo, Brazil.
    Terrett, D.
    Rutherford Appleton Lab, STFC, Harwell OX11 0QX, Didcot, England.
    Teyssandier, P.
    Sorbonne Univ, LNE, Univ PSL, Observ Paris,SYRTE,CNRS, 61 Ave Observ, F-75014 Paris, France.
    Thuillot, W.
    Univ Lille, Sorbonne Univ, Univ PSL, Observ Paris,IMCCE, 77 Av Denfert Rochereau, F-75014 Paris, France.
    Titarenko, A.
    Univ Cote Azur, Observ Cote Azur, CNRS, Lab Lagrange, Bd Observ,CS 34229, F-06304 Nice 4, France.
    Clotet, F. Torra
    Aarhus Univ, Stellar Astrophys Ctr, Dept Phys & Astron, 120 Ny Munkegade,Bldg 1520, DK-8000 Aarhus, Denmark.
    Turon, C.
    Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Ulla, A.
    Univ Bonn, Argelander Inst Astron, Hugel 71, D-53121 Bonn, Germany.
    Utrilla, E.
    ESA ESAC, Aurora Technol, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    Uzzi, S.
    ALTEC SpA, Corso Marche 79, I-10146 Turin, Italy.
    Vaillant, M.
    CNES Ctr Spatial Toulouse, Thales Serv, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Valentini, G.
    INAF, Osservatorio Astron Abruzzo, Via Mentore Maggini, I-64100 Teramo, Italy.
    Valette, V.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    van Elteren, A.
    Leiden Univ, Leiden Observ, Niels Bohrweg 2, NL-2333 CA Leiden, Netherlands.
    Van Hemelryck, E.
    Royal Observ Belgium, Ringlaan 3, B-1180 Brussels, Belgium.
    Vaschetto, M.
    ALTEC SpA, Corso Marche 79, I-10146 Turin, Italy.
    Vecchiato, A.
    INAF Osservatorio Astrofis Torino, Via Osservatorio 20, I-10025 Pino Torinese, Italy.
    Veljanoski, J.
    Univ Groningen, Kapteyn Astron Inst, Landleven 12, NL-9747 AD Groningen, Netherlands.
    Viala, Y.
    Univ PSL, GEPI, Observ Paris, CNRS, 5 Pl Jules Janssen, F-92190 Meudon, France.
    Vicente, D.
    Ctr Nacl Super Comp, Barcelona Supercomputing Ctr, C Jordi Girona 29,Ed Nexus 2, Barcelona 08034, Spain.
    Vogt, S.
    ESA ESAC, QUASAR Sci Resources, Camino Bajo Castillo S-N, Madrid 28692, Spain.
    von Essen, C.
    Australian Natl Univ, Res Sch Astron & Astrophys, Canberra, ACT 2611, Australia.
    Voss, H.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Votruba, V.
    Acad Sci Czech Republ, Astron Inst, Fricova 298, Ondrejov 25165, Czech Republic.
    Voutsinas, S.
    Univ Edinburgh, Royal Observ, Inst Astron, Blackford Hill, Edinburgh EH9 3HJ, Midlothian, Scotland.
    Walmsley, G.
    CNES Ctr Spatial Toulouse, 18 Ave Edouard Belin, F-31401 Toulouse 9, France.
    Weiler, M.
    Univ Barcelona, Inst Ciencies Cosmos, IEEC UB, Marti I Franques 1, Barcelona 08028, Spain.
    Wertz, O.
    Sorbonne Univ, UPMC Univ, Paris 6 & CNRS, UMR 7095,Inst Astrophys Paris, 98 Bis Bd Arago, F-75014 Paris, France.
    Wevers, T.
    Radboud Univ Nijmegen, Dept Astrophys, IMAPP, POB 9010, NL-6500 GL Nijmegen, Netherlands;Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Wyrzykowski, L.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England;Univ Warsaw Observ, Al Ujazdowskie 4, PL-00478 Warsaw, Poland.
    Yoldas, A.
    Univ Cambridge, Inst Astron, Madingley Rd, Cambridge CB3 0HA, England.
    Zerjal, M.
    Tel Aviv Univ, Dept Geosci, IL-6997801 Tel Aviv, Israel;Univ Ljubljana, Fac Math & Phys, Jadranska Ulica 19, Ljubljana 1000, Slovenia.
    Ziaeepour, H.
    Univ Bourgogne Franche Comte, Inst UTINAM UMR6213, CNRS, OSU THETA Franche Comte Bourgogne, F-25000 Besancon, France.
    Zorec, J.
    Zschocke, S.
    Tech Univ Dresden, Lohrmann Observ, Mommsenstr 13, D-01062 Dresden, Germany.
    Zucker, S.
    Zurbach, C.
    Univ Montpellier, Lab Univ & Particules Montpellier, Pl Eugene Bataillon,CC72, F-34095 Montpellier 05, France.
    Zwitter, T.
    Univ Ljubljana, Fac Math & Phys, Jadranska Ulica 19, Ljubljana 1000, Slovenia.
    Observational Hertzsprung-Russell diagrams2018Inngår i: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 616, artikkel-id A10Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Context. Gaia Data Release 2 provides high-precision astrometry and three-band photometry for about 1.3 billion sources over the full sky. The precision, accuracy, and homogeneity of both astrometry and photometry are unprecedented. Aims. We highlight the power of the Gaia DR2 in studying many fine structures of the Hertzsprung-Russell diagram (HRD). Gaia allows us to present many different HRDs, depending in particular on stellar population selections. We do not aim here for completeness in terms of types of stars or stellar evolutionary aspects. Instead, we have chosen several illustrative examples. Methods. We describe some of the selections that can be made in Gaia DR2 to highlight the main structures of the Gaia HRDs. We select both field and cluster (open and globular) stars, compare the observations with previous classifications and with stellar evolutionary tracks, and we present variations of the Gaia HRD with age, metallicity, and kinematics. Late stages of stellar evolution such as hot subdwarfs, post-AGB stars, planetary nebulae, and white dwarfs are also analysed, as well as low-mass brown dwarf objects. Results. The Gaia HRDs are unprecedented in both precision and coverage of the various Milky Way stellar populations and stellar evolutionary phases. Many fine structures of the HRDs are presented. The clear split of the white dwarf sequence into hydrogen and helium white dwarfs is presented for the first time in an HRD. The relation between kinematics and the HRD is nicely illustrated. Two different populations in a classical kinematic selection of the halo are unambiguously identified in the HRD. Membership and mean parameters for a selected list of open clusters are provided. They allow drawing very detailed cluster sequences, highlighting fine structures, and providing extremely precise empirical isochrones that will lead to more insight in stellar physics. Conclusions. Gaia DR2 demonstrates the potential of combining precise astrometry and photometry for large samples for studies in stellar evolution and stellar population and opens an entire new area for HRD-based studies.

  • 17. Bagnulo, S.
    et al.
    Fossati, L.
    Kochukhov, Oleg
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Landstreet, J. D.
    The importance of non-photon noise in stellar spectropolarimetry The spurious detection of a non-existing magnetic field in the AO supergiant HD 922072013Inngår i: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 559, s. A103-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Context. The low-resolution, Cassegrain mounted, FORS spectropolarimeter of the ESO Very Large Telescope is being extensively used for magnetic field surveys. Some of the new discoveries suggest that relatively strong magnetic fields may play an important role in numerous physical phenomena observed in the atmospheres as well as in the circumstellar environments of certain kinds of stars. Aims. We show in detail how small instabilities or data-reduction inaccuracies represent an alternative explanation for the origin of certain signals of circular polarisation published in recent years. Methods. With the help of analytical calculations we simulate the observation of a spectral line in spectropolarimetric mode, adding very small spurious wavelength shifts, which may mimic the effects of seeing variations, rapid variations of the stellar radial velocity, or instrument instabilities. As a case study, we then re-visit the FORS2 measurements that have been used to claim the discovery of a magnetic field in the A0 supergiant HD 92207. In addition, we present new observations of this star obtained with the HARPSpol instrument. Results. Both calibration and science data show compelling evidence that photon-noise is not the only source of error in magnetic field measurements, especially in sharp spectral lines. Non-photon noise may be kept under control by accurate data reduction and quality controls. Our re-analysis of FORS2 observations of HD 92207 shows no evidence of a magnetic field, and we are able to reproduce the previous FORS detection only by degrading the quality of our wavelength calibration. Our HARPSpol spectropolarimetric measurements show no evidence of a magnetic field at the level of 10 G. Conclusions. Our work contributes to a better understanding of the importance of accurate data treatment and instrument characterisation, and demonstrates that ultra-high signal-to-noise ratio measurements do not automatically translate into ultra-high accuracy.

  • 18. Bagnulo, S.
    et al.
    Landstreet, J. D.
    Fossati, L.
    Kochukhov, O.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Stellar magnetism through the polarized eyes of the FORS1 instrument2012Inngår i: American Institute of Physics Conference Series, American Institute of Physics (AIP), 2012, Vol. 1429, s. 57-66Konferansepaper (Fagfellevurdert)
  • 19. Bagnulo, S.
    et al.
    Landstreet, J. D.
    Fossati, L.
    Kochukhov, Oleg
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Magnetic field measurements and their uncertainties: the FORS1 legacy2012Inngår i: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 538, s. A129-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Context. During the last decade, the FORS1 instrument of the ESO Very Large Telescope has been extensively used to study stellar magnetism. A number of interesting discoveries of magnetic fields in several classes of stars have been announced, many of which obtained at a similar to 3 sigma level; some of the discoveries are confirmed by measurements obtained with other instruments, some are not.

    Aims. We investigate the reasons for the discrepancies between the results obtained with FORS1 and those obtained with other instruments.

    Methods. Using the ESO FORS pipeline, we have developed a semi-automatic procedure for magnetic field determination. We have applied this procedure to the full content of circular spectropolarimetric measurements of the FORS1 archive (except for most of the observations obtained in multi-object spectropolarimetric mode). We have devised and applied a number of consistency checks to our field determinations, and we have compared our results to those previously published in the literature.

    Results. We find that for high signal-to-noise ratio measurements, photon noise does not account for the full error bars. We discuss how field measurements depend on the specific algorithm adopted for data reduction, and we show that very small instrument flexures, negligible in most of the instrument applications, may be responsible for some spurious field detections in the null profiles. Finally, we find that we are unable to reproduce some results previously published in the literature. Consequently, we do not confirm some important discoveries of magnetic fields obtained with FORS1 and reported in previous publications.

    Conclusions. Our revised field measurements show that there is no contradiction between the results obtained with the low-resolution spectropolarimeter FORS1 and those obtained with high-resolution spectropolarimeters. FORS1 is an instrument capable of performing reliable magnetic field measurements, provided that the various sources of uncertainties are properly taken into account.

  • 20. Bailer-Jones, C. A. L.
    et al.
    Andrae, R.
    Arcay, B.
    Astraatmadja, T.
    Bellas-Velidis, I.
    Berihuete, A.
    Bijaoui, A.
    Carrion, C.
    Dafonte, C.
    Damerdji, Y.
    Dapergolas, A.
    de Laverny, P.
    Delchambre, L.
    Drazinos, P.
    Drimmel, R.
    Fremat, Y.
    Fustes, D.
    Garcia-Torres, M.
    Guede, C.
    Heiter, Ulrike
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Janotto, A. -M
    Karampelas, A.
    Kim, D. -W
    Knude, J.
    Kolka, I.
    Kontizas, E.
    Kontizas, M.
    Korn, Andreas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi.
    Lanzafame, A. C.
    Lebreton, Y.
    Lindstrom, H.
    Liu, C.
    Livanou, E.
    Lobel, A.
    Manteiga, M.
    Martayan, C.
    Ordenovic, Ch.
    Pichon, B.
    Recio-Blanco, A.
    Rocca-Volmerange, B.
    Sarro, L. M.
    Smith, K.
    Sordo, R.
    Soubiran, C.
    Surdej, J.
    Thevenin, F.
    Tsalmantza, P.
    Vallenari, A.
    Zorec, J.
    The Gaia astrophysical parameters inference system (Apsis) Pre-launch description2013Inngår i: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 559, s. A74-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Gaia satellite will survey the entire celestial sphere down to 20th magnitude, obtaining astrometry, photometry, and low resolution spectrophotometry on one billion astronomical sources, plus radial velocities for over one hundred million stars. Its main objective is to take a census of the stellar content of our Galaxy, with the goal of revealing its formation and evolution. Gaia's unique feature is the measurement of parallaxes and proper motions with hitherto unparalleled accuracy for many objects. As a survey, the physical properties of most of these objects are unknown. Here we describe the data analysis system put together by the Gaia consortium to classify these objects and to infer their astrophysical properties using the satellite's data. This system covers single stars, (unresolved) binary stars, quasars, and galaxies, all covering a wide parameter space. Multiple methods are used for many types of stars, producing multiple results for the end user according to different models and assumptions. Prior to its application to real Gaia data the accuracy of these methods cannot be assessed definitively. But as an example of the current performance, we can attain internal accuracies (rms residuals) on F, G, K, M dwarfs and giants at G = 15 (V = 15-17) for a wide range of metallicites and interstellar extinctions of around 100 K in effective temperature (T-eff), 0.1 mag in extinction (A(0)), 0.2 dex in metallicity ([Fe/H]), and 0.25 dex in surface gravity (log g). The accuracy is a strong function of the parameters themselves, varying by a factor of more than two up or down over this parameter range. After its launch in December 2013, Gaia will nominally observe for five years, during which the system we describe will continue to evolve in light of experience with the real data.

  • 21. Bailey, J. D.
    et al.
    Landstreet, J. D.
    Bagnulo, S.
    Fossati, L.
    Kochukhov, Oleg
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Paladini, C.
    Silvester, J.
    Wade, G.
    Magnetic field and atmospheric chemical abundances of the magnetic Ap star HD 3181072011Inngår i: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 535, s. A25-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Context. A new generation of powerful and efficient spectropolarimeters has recently been used to provide the first sample of magnetic Ap stars of accurately known ages. Modelling of these data offer the possibility of significant new insights into the physics and main sequence evolution of these remarkable stars.

    Aims. New spectra have been obtained with the ESPaDOnS spectropolarimeter, and are supplemented with unpolarised spectra from the ESO UVES, UVES-FLAMES, and HARPS spectrographs, of the very peculiar large-field magnetic Ap star HD 318107, a member of the open cluster NGC 6405 and thus a star with a well-determined age. The available data provide sufficient material with which to re-analyse the first-order model of the magnetic field geometry and to derive chemical abundances of Si, Ti, Fe, Nd, Pr, Mg, Cr, Mn, O, and Ca.

    Methods. The models were obtained using ZEEMAN, a program which synthesises spectral line profiles for stars that have magnetic fields. The magnetic field structure was modelled with a low-order colinear multipole expansion, using coefficients derived from the observed variations of the field strength with rotation phase. The abundances of several elements were determined using spectral synthesis. After experiments with a very simple model of uniform abundance on each of three rings of equal width in co-latitude and symmetric about the assumed magnetic axis, we decided to model the spectra assuming uniform abundances of each element over the stellar surface.

    Results. The new magnetic field measurements allow us to refine the rotation period of HD 318107 to P = 9.7088 +/- 0.0007 days. Appropriate magnetic field model parameters were found that very coarsely describe the (apparently rather complex) field moment variations. Spectrum synthesis leads to the derivation of mean abundances for the elements Mg, Si, Ca, Ti, Cr, Fe, Nd, and Pr. All of these elements except for Mg and Ca are strongly overabundant compared to the solar abundance ratios. There is considerable evidence of non-uniformity, for example in the different values of < B(z)> found using lines of different elements.

    Conclusions. The present data set, while limited, is nevertheless sufficient to provide a useful first-order assessment of both the magnetic and surface abundance properties of HD 318107, making it one of the very few magnetic Ap stars of well-known age for which both of these properties have been studied.

  • 22.
    Barklem, Paul S.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Teoretisk astrofysik.
    Excitation and charge transfer in low-energy hydrogen-atom collisions with neutral atoms: Theory, comparisons, and application to Ca2016Inngår i: PHYSICAL REVIEW A, ISSN 2469-9926, Vol. 93, nr 4, artikkel-id 042705Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A theoretical method is presented for the estimation of cross sections and rates for excitation and charge-transfer processes in low-energy hydrogen-atom collisions with neutral atoms, based on an asymptotic two-electron model of ionic-covalent interactions in the neutral atom-hydrogen-atom system. The calculation of potentials and nonadiabatic radial couplings using the method is demonstrated. The potentials are used together with the multichannel Landau-Zener model to calculate cross sections and rate coefficients. The main feature of the method is that it employs asymptotically exact atomic wave functions, which can be determined from known atomic parameters. The method is applied to Li + H, Na + H, and Mg + H collisions, and the results compare well with existing detailed full-quantum calculations. The method is applied to the astrophysically important problem of Ca + H collisions, and rate coefficients are calculated for temperatures in the range 1000-20 000 K.

  • 23.
    Barklem, Paul S.
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Teoretisk astrofysik.
    Collet, R.
    Australian Natl Univ, Res Sch Astron & Astrophys, Canberra, ACT 2611, Australia.;Aarhus Univ, Dept Phys & Astron, Stellar Astrophys Ctr, Ny Munkegade 120, DK-8000 Aarhus C, Denmark..
    Partition functions and equilibrium constants for diatomic molecules and atoms of astrophysical interest2016Inngår i: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 588, artikkel-id A96Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Partition functions and dissociation equilibrium constants are presented for 291 diatomic molecules for temperatures in the range from near absolute zero to 10 000 K, thus providing data for many diatomic molecules of astrophysical interest at low temperature. The calculations are based on molecular spectroscopic data from the book of Huber & Herzberg (1979, Constants of Diatomic Molecules) with significant improvements from the literature, especially updated data for ground states of many of the most important molecules by Irikura (2007, J. Phys. Chem. Ref. Data, 36, 389). Dissociation energies are collated from compilations of experimental and theoretical values. Partition functions for 284 species of atoms for all elements from H to U are also presented based on data collected at NIST. The calculated data are expected to be useful for modelling a range of low density astrophysical environments, especially star-forming regions, protoplanetary disks, the interstellar medium, and planetary and cool stellar atmospheres. The input data, which will be made available electronically, also provides a possible foundation for future improvement by the community.

  • 24. Bedding, Timothy R.
    et al.
    Kjeldsen, Hans
    Campante, Tiago L.
    Appourchaux, Thierry
    Bonanno, Alfio
    Chaplin, William J.
    Garcia, Rafael A.
    Martic, Milena
    Mosser, Benoit
    Butler, R. Paul
    Bruntt, Hans
    Kiss, Laszlo L.
    O'Toole, Simon J.
    Kambe, Eiji
    Ando, Hiroyasu
    Izumiura, Hideyuki
    Sato, Bun'ei
    Hartmann, Michael
    Hatzes, Artie
    Barban, Caroline
    Berthomieu, Gabrielle
    Michel, Eric
    Provost, Janine
    Turck-Chieze, Sylvaine
    Lebrun, Jean-Claude
    Schmitt, Jerome
    Bertaux, Jean-Loup
    Benatti, Serena
    Claudi, Riccardo U.
    Cosentino, Rosario
    Leccia, Silvio
    Frandsen, Soren
    Brogaard, Karsten
    Glowienka, Lars
    Grundahl, Frank
    Stempels, Eric
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Arentoft, Torben
    Bazot, Michael
    Christensen-Dalsgaard, Jorgen
    Dall, Thomas H.
    Karoff, Christoffer
    Lundgreen-Nielsen, Jens
    Carrier, Fabien
    Eggenberger, Patrick
    Sosnowska, Danuta
    Wittenmyer, Robert A.
    Endl, Michael
    Metcalfe, Travis S.
    Hekker, Saskia
    Reffert, Sabine
    A multi-site campaign to measure solar-like oscillations in Procyon. II. mode frequencies2010Inngår i: Astrophysical Journal, ISSN 0004-637X, E-ISSN 1538-4357, Vol. 713, nr 2, s. 935-949Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We have analyzed data from a multi-site campaign to observe oscillations in the F5 star Procyon. The data consist of high-precision velocities that we obtained over more than three weeks with 11 telescopes. A new method for adjusting the data weights allows us to suppress the sidelobes in the power spectrum. Stacking the power spectrum in a so-called echelle diagram reveals two clear ridges, which we identify with even and odd values of the angular degree (l = 0 and 2, and l = 1 and 3, respectively). We interpret a strong, narrow peak at 446 mu Hz that lies close to the l = 1 ridge as a mode with mixed character. We show that the frequencies of the ridge centroids and their separations are useful diagnostics for asteroseismology. In particular, variations in the large separation appear to indicate a glitch in the sound-speed profile at an acoustic depth of similar to 1000 s. We list frequencies for 55 modes extracted from the data spanning 20 radial orders, a range comparable to the best solar data, which will provide valuable constraints for theoretical models. A preliminary comparison with published models shows that the offset between observed and calculated frequencies for the radial modes is very different for Procyon than for the Sun and other cool stars. We find the mean lifetime of the modes in Procyon to be 1.29(-0.49)(+0.55) days, which is significantly shorter than the 2-4 days seen in the Sun.

  • 25. Benedict, G. Fritz
    et al.
    McArthur, Barbara E.
    Feast, Michael W.
    Barnes, Thomas G.
    Harrison, Thomas E.
    Bean, Jacob L.
    Menzies, John W.
    Chaboyer, Brian
    Fossati, Luca
    Nesvacil, Nicole
    Smith, Horace A.
    Kolenberg, Katrien
    Laney, C. D.
    Kochukhov, Oleg
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Nelan, Edmund P.
    Shulyak, D. V.
    Taylor, Denise
    Freedman, Wendy L.
    Distance scale zero points from galactic RR Lyrae star parallaxes2011Inngår i: Astronomical Journal, ISSN 0004-6256, E-ISSN 1538-3881, Vol. 142, nr 6, s. 187-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We present new absolute trigonometric parallaxes and proper motions for seven Population II variable stars-five RR Lyr variables: RZ Cep, XZ Cyg, SU Dra, RR Lyr, and UV Oct; and two type 2 Cepheids: VY Pyx and kappa Pav. We obtained these results with astrometric data from Fine Guidance Sensors, white-light interferometers on Hubble Space Telescope. We find absolute parallaxes in milliseconds of arc: RZ Cep, 2.12 +/- 0.16 mas; XZ Cyg, 1.67 +/- 0.17 mas; SU Dra, 1.42 +/- 0.16 mas; RR Lyr, 3.77 +/- 0.13 mas; UV Oct, 1.71 +/- 0.10 mas; VY Pyx, 6.44 +/- 0.23 mas; and. Pav, 5.57 +/- 0.28 mas; an average sigma(pi)/pi = 5.4%. With these parallaxes, we compute absolute magnitudes in V and K bandpasses corrected for interstellar extinction and Lutz-Kelker-Hanson bias. Using these RR Lyrae variable star absolute magnitudes, we then derive zero points for M(V)-[Fe/H] and M(K)-[Fe/H]-log P relations. The technique of reduced parallaxes corroborates these results. We employ our new results to determine distances and ages of several Galactic globular clusters and the distance of the Large Magellanic Cloud. The latter is close to that previously derived from Classical Cepheids uncorrected for any metallicity effect, indicating that any such effect is small. We also discuss the somewhat puzzling results obtained for our two type 2 Cepheids.

  • 26. Bergemann, M.
    et al.
    Ruchti, G. R.
    Serenelli, A.
    Feltzing, S.
    Alves-Brito, A.
    Asplund, M.
    Bensby, T.
    Gruyters, Pieter
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi.
    Heiter, Ulrike
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Hourihane, A.
    Korn, Andreas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Teoretisk astrofysik.
    Lind, K.
    Marino, A.
    Jofre, P.
    Nordlander, T.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi.
    Ryde, N.
    Worley, C. C.
    Gilmore, G.
    Randich, S.
    Ferguson, A. M. N.
    Jeffries, R. D.
    Micela, G.
    Negueruela, I.
    Prusti, T.
    Rix, H. -W
    Vallenari, A.
    Alfaro, E. J.
    Allende Prieto, C.
    Bragaglia, A.
    Koposov, S. E.
    Lanzafame, A. C.
    Pancino, E.
    Recio-Blanco, A.
    Smiljanic, R.
    Walton, N.
    Costado, M. T.
    Franciosini, E.
    Hill, V.
    Lardo, C.
    de Laverny, P.
    Magrini, L.
    Maiorca, E.
    Masseron, T.
    Morbidelli, L.
    Sacco, G.
    Kordopatis, G.
    Tautvaisiene, G.
    The Gaia-ESO Survey: radial metallicity gradients and age-metallicity relation of stars in the Milky Way disk2014Inngår i: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 565, s. A89-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We study the relationship between age, metallicity, and alpha-enhancement of FGK stars in the Galactic disk. The results are based upon the analysis of high-resolution UVES spectra from the Gaia-ESO large stellar survey. We explore the limitations of the observed dataset, i.e. the accuracy of stellar parameters and the selection effects that are caused by the photometric target preselection. We find that the colour and magnitude cuts in the survey suppress old metal-rich stars and young metal-poor stars. This suppression may be as high as 97% in some regions of the age-metallicity relationship. The dataset consists of 144 stars with a wide range of ages from 0.5 Gyr to 13.5 Gyr, Galactocentric distances from 6 kpc to 9.5 kpc, and vertical distances from the plane 0 < vertical bar Z vertical bar < 1.5 kpc. On this basis, we find that i) the observed age-metallicity relation is nearly flat in the range of ages between 0 Gyr and 8 Gyr; ii) at ages older than 9 Gyr, we see a decrease in [Fe/H] and a clear absence of metal-rich stars; this cannot be explained by the survey selection functions; iii) there is a significant scatter of [Fe/H] at any age; and iv) [Mg/Fe] increases with age, but the dispersion of [Mg/Fe] at ages > 9 Gyr is not as small as advocated by some other studies. In agreement with earlier work, we find that radial abundance gradients change as a function of vertical distance from the plane. The [Mg/Fe] gradient steepens and becomes negative. In addition, we show that the inner disk is not only more alpha-rich compared to the outer disk, but also older, as traced independently by the ages and Mg abundances of stars.

  • 27.
    Bergvall, Nils
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Star Forming Dwarf Galaxies2012Inngår i: DWARF GALAXIES: KEYS TO GALAXY FORMATION AND EVOLUTION: PROCEEDINGS OF SYMPOSIUM 3 OF JENAM 2010, 2012, s. 175-194Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Star forming dwarf galaxies (SFDGs) have a high gas content and low metallicities, reminiscent of the basic entities in hierarchical galaxy formation scenarios. In the young universe they probably also played a major role in the cosmic reionization. Their abundant presence in the local volume and their youthful character make them ideal objects for detailed studies of the initial stellar mass function (IMF), fundamental star formation processes and its feedback to the interstellar medium. Occasionally we witness SFDGs involved in extreme starbursts, giving rise to strongly elevated production of super star clusters and global superwinds, mechanisms yet to be explored in more detail. SFDGs is the initial state of all dwarf galaxies and the relation to the environment provides us with a key to how different types of dwarf galaxies are emerging. In this review we will put the emphasis on the exotic starburst phase, as it seems less important for present day galaxy evolution but perhaps fundamental in the initial phase of galaxy formation.

  • 28.
    Bergvall, Nils
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Leitet, Elisabet
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Zackrisson, Erik
    Department of Astronomy, Stockholm University, Oscar Klein Center, AlbaNova, Stockholm.
    Marquart, Thomas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Lyman continuum leaking galaxies: Search strategies and local candidates2013Inngår i: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 554, s. A38-Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    Context. Star-forming dwarf galaxies may have played an important role in the reionization of the Universe, provided that some fraction of their ionizing radiation were able to escape into the intergalactic medium. Local galaxies exhibiting such Lyman-continuum(LyC) leakage could potentially shed light on the escape mechanisms involved, but only two low-redshift cases of LyC leakage have been identified so far. Here, we argue that this meager harvest may be caused by unsuitable selection criteria. Candidates for LyC leakage are normally selected by indicators of starburst activity, one of which is a high equivalent width in H alpha. Such a criterion will guarantee a high production of LyC photons but will also bias the selection in favour of a high column density in the neutral gas, effectively ruling out LyC escape. Aims. In this work we want to investigate whether the lack of local LyC emitters can be caused in part by biased selection criteria, and we present a novel method of selecting targets with high escape fractions. By applying these criteria, we assemble a sample of observation targets to study their basic properties. Methods. We introduce a new selection strategy here where the potential LyC leakers are selected by their blue colours and weak emission lines. The selection is based on data from the Sloan Digital Sky Survey (SDSS). We also take a closer look at the properties of 8 LyCleaking candidates at z similar to 0.03 which we have observed with ESO/NTT in broadband B and H alpha. Results. We find that 7 of the 8 target galaxies are involved in interaction with neighbours or show signs of mergers. In 7 cases the young stellar population is clearly displaced relative to the main body of these galaxies, often directly bordering the halo region. In about half of our targets the absorption spectra show young post-starburst signatures. Comparing the scale lengths in H alpha with those of the stellar continua shows that the scale lengths in H alpha typically are 30% smaller, which is characteristic of galaxies influenced by ram pressure stripping. We tentatively identify a few mechanisms that could improve the conditions for leakage: 1) the combined effects of ram pressure stripping with supernova winds from young stars formed in the front, 2) merger events that increase the star formation rate and displace stars from gas, 3) starbursts in the centres of post-starburst galaxies, whose previous activity has cleared channels for leakage into the intergalactic medium, and 4) a low dust content. Although our target galaxies are rare species in the local universe, we argue that related types could have played a major role in producing ionizing radiation at high redshifts.

  • 29.
    Bergvall, Nils
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Marquart, Thomas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Way, Michael J.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik. NASA Goddard Institute for Space Studies, 2880 Broadway, New York 10025, USA.
    Blomqvist, Anna
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Holst, Emma
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Östlin, Göran
    Stockholm Univ, Dept Astron, S-10691 Stockholm, Sweden.
    Zackrisson, Erik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Fysiska sektionen, Institutionen för fysik och astronomi, Observationell astrofysik.
    Local starburst galaxies and their descendants: Statistics from the Sloan Digital Sky Survey2016Inngår i: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 587, artikkel-id A72Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aims: Despite strong interest in the starburst phenomenon in extragalactic astronomy, the concept remains ill-defined. Here we use a strict definition of starburst to examine the statistical properties of starburst galaxies in the local universe. We also seek to establish links between starburst galaxies, post-starburst (hereafter postburst) galaxies, and active galaxies.

    Methods: Data were selected from the Sloan Digital Sky Survey DR7. We applied a novel method of treating dust attenuation and derive star formation rates, ages, and stellar masses assuming a two-component stellar population model. Dynamical masses are calculated from the width of the H alpha line. These masses agree excellently with the photometric masses. The mass (gas + stars) range is similar to 10(9)-10(11.5) M-circle dot. As a selection criterion for starburst galaxies, we use, the birthrate parameter, b = SFR/< SFR >, requiring that b >= 3. For postburst galaxies, we use, the equivalent width of H delta in absorption with the criterion EWH delta,abs >= 6 angstrom.

    Results: We find that only 1% of star-forming galaxies are starburst galaxies. They contribute 3 6% to the stellar production and are therefore unimportant for the local star formation activity. The median starburst age is 70 Myr roughly independent of mass, indicating that star formation is mainly regulated by local feedback processes. The b-parameter strongly depends on burst age. Values close to b = 60 are found at ages similar to 10 Myr, while almost no starbursts are found at ages >1 Gyr. The median baryonic burst mass fraction of sub-L* galaxies is 5% and decreases slowly towards high masses. The median mass fraction of the recent burst in the postburst sample is 5-10%. A smaller fraction of the postburst galaxies, however, originates in non-bursting galaxies. The age-mass distribution of the postburst progenitors (with mass fractions >3%) is bimodal with a break at log M (M-circle dot) similar to 10.6, above which the ages are doubled. The starburst and postburst luminosity functions (LFs) follow each other closely until M-r similar to -21, when active galactic nuclei (AGNs) begin to dominate. The postburst LF continues to follow the AGN LF, while starbursts become less significant. This suggests that the number of luminous starbursts is underestimated by about one dex at high luminosities, because of having large amounts of dust and/or being outshone by an AGN. It also indicates that the starburst phase preceded the AGN phase. Finally, we look at the conditions for global gas outflow caused by stellar feedback and find that massive starburst galaxies are susceptible to such outflows.

  • 30.
    Bertelli Motta, C.
    et al.
    Heidelberg Univ, Zentrum Astron, Astron Rechen Inst, Monchhofstr 12-14, D-69120 Heidelberg, Germany.