Spectroscopic monitoring of active galactic nuclei. III. Size of the broad line region in NGC 3227
1994 (English)In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 282, no 3, 742-752752 p.Article in journal (Refereed) Published
For pt.II see ibid., vol.269, no.1-2, p.39-53 (1993). The authors present the results of a five-month monitoring campaign of the active galactic nucleus in NGC 3227. The Hbeta and Halpha emission lines and the optical continuum have been analysed. The optical AGN continuum and the broad-line region (BLR) emission in NGC 3227 appear to vary by about 40% on a timescale of 1.5 month. The levels of the broad-line emission and the 675.0 nm continuum are well correlated, a fact consistent with the assumption that the BLR material is photoionised by the central continuum source. Cross-correlation analyses between the light curves of the 675.0 nm AGN continuum and the BLR H emission indicate that the lag of the BLR emission with respect to the continuum variations is 17plusmn7 days. This result suggests that the BLR clouds that are affected by the changes in the flux of the central ionising source lie about 17 light days away from it
Place, publisher, year, edition, pages
1994. Vol. 282, no 3, 742-752752 p.
Experimental/ astronomical photometry, astronomical spectra, galactic nuclei, visible astronomical observations/ AGN broad line region size, spectrum variations, visible, BLR clouds galactocentric distance, emission-line spectrum, BLR size-nuclear luminosity relation, AD 1990 01 to 06, light curves cross-correlation analyses, interacting galaxy, BLR clouds photoionisation, active galactic nuclei, NGC 3227, five-month monitoring campaign, active galactic nucleus, Hbeta, emission lines, optical continuum, broad-line region, 675.0 nm continuum, central continuum source, BLR H emission, continuum variations, BLR clouds, central ionising source, 486.1 nm, 656.3 nm, 675.0 nm, 45 d, 10 to 24 d, 17 d, 440 Tm, 260 to 620 Tm, 23 Mpc, 450 to 700 nm, 1158 km/s, H emission line variations time lag/ A9850R Active and peculiar galaxies A9850E Galactic structure, content and morphology A9850G Radiation and spectra of galaxies A9580J Photographic region astronomical observations/ wavelength 4.861E-07 m, wavelength 6.563E-07 m, wavelength 6.75E-07 m, time 3.9E+06 s, time 8.6E+05 to 2.1E+06 s, time 1.5E+06 s, distance 4.4E+14 m, distance 2.6E+14 to 6.2E+14 m, galactic distance 2.3E+07 pc, wavelength 4.5E-07 to 7.0E-07 m, velocity 1.158E+06 m/s/ H/el
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:uu:diva-197169ISI: 4678154OAI: oai:DiVA.org:uu-197169DiVA: diva2:611950