Broadband UBVRCIC photometry of horizontal-branch and metal-poor candidates from the HK and Hamburg/ESO surveys. I.
2007 (English)In: Astrophysical Journal Supplement Series, ISSN 0067-0049, E-ISSN 1538-4365, Vol. 168, no 1, 128-139 p.Article in journal (Refereed) Published
We report broadband UBV and/or BVRCIC CCD photometry for a total of 1857 stars in the thick-disk and halo populations of the Galaxy. The majority of our targets were selected as candidate field horizontal-branch or other A-type stars (FHB/ A, N = 576), or candidate low-metallicity stars (N = 1221), from the HK and Hamburg/ESO objective-prism surveys. Similar data for a small number of additional stars from other samples are also reported. These data are being used for several purposes. In the case of the FHB/ A candidates they are used to accurately separate the lower gravity FHB stars from various higher gravity A-type stars, a subsample that includes the so-called blue metal poor stars, halo and thick-disk blue stragglers, main-sequence A-type dwarfs, and Am and Ap stars. These data are also being used to derive photometric distance estimates to high-velocity hydrogen clouds in the Galaxy and for improved measurements of the mass of the Galaxy. Photometric data for the metal-poor candidates are being used to refine estimates of stellar metallicity for objects with available medium-resolution spectroscopy, to obtain distance estimates for kinematic analyses, and to establish initial estimates of effective temperature for analysis of high-resolution spectroscopy of the stars for which this information now exists.
Place, publisher, year, edition, pages
2007. Vol. 168, no 1, 128-139 p.
stars : early-type, stars : horizontal-branch, stars : Population II, techniques : photometric
IdentifiersURN: urn:nbn:se:uu:diva-146642DOI: 10.1086/509324ISI: 000243387200005OAI: oai:DiVA.org:uu-146642DiVA: diva2:399183