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CONTINUUM AND BROAD EMISSION LINE VARIABILITY OF SEYFERT GALAXIES
V.T. Doroshenko1,2 , S.G. Sergeev2 , V.I. Pronik
1 2

Crimean Lab. of the Sternberg Astronomical Institute, Moscow University, Russia 2 Scientific-Research Institute, Crimean Astrophysical Observatory, Ukraine; p/o Nauchny, 98409, Crimea, Ukraine vdorosh@sai.crimea.ua

We fo cused on the observed prop erties of some Seyfert galaxies without detailed discussion of underlying physical mechanisms. Our purp ose was to show a diversity of observed effects due to variability in sp ectra of six galaxies (NGC 4151, NGC 5548, Mrk 6, Ark 120, 3C 390.3, Arp 120B), optical sp ectral and photometric monitoring of which was carried out in the Crimean Astrophysical Observatory and Crimean Lab oratory of the Sternb erg Astronomical Institute over many years. This monitoring shows that · All light curves demonstrate a variability on different time scales from days to years. · Amplitude of variations increases with increasing of the time interval of observations. · The flux in emission lines changes in resp onse to the flux variation of the ionizing continuum source with some time delay. Thus, the emission lines "echo" or "reverb erate" the continuum changes. This time delay is due to light-travel time effects within the BLR. · The time delay of the broad H emission line flux relative to optical continuum in the vicinity of the H line lies in an interval from 9.2 days for Arp 102B to 80 days for 3C 390.3. This means that a region of the most effective emission in the H and H lines is fairly small, and it is lo cated at a distance of ab out 9 80 light days from the continuum source. · We found one very strange and inexplicable case (3C 390.3) when a lag calculated from the broad H line significantly exceeds that of the H . In all other cases, the H and H lines have a similar lag. · We revealed a slightly different lag for two time intervals for NGC 5548: 26 days in 19721988 and 18 days in 19892001. · Analysis of the lag as a function of the radial velo city do es not show any reliable evidence of the pure radial dominated outflow, p ossibly, except for NGC 4151. A weak evidence of radial inflow was found in Mrk 6 and Ark 120. Predominantly, we found that there is no pure radial inflow or outflow in the BLR of the considered galaxies. In all cases, the kinematics mainly lo oks like a chaotic or rotational motion. · We also found that the lag for the central part of the broad H emission line is slightly larger than for wings (NGC 5548). · The lag slightly increases with increasing of the continuum flux (Ark 120). This fact is consistent with a virial relation b etween the velo city field and the distance of the emitting region: the velo city field diminishes with increasing distance from

the central continuum source. This implies that the velo city field is dominated by a central massive ob ject. · Not only the flux of broad emission line but also the line profiles appreciably changed with time. The emission-line profile changes usually o ccur on a time scale that is much longer than the light-travel time scale. · In all cases, the excess b etween the normalized Balmer profiles and the mean normalized profile shows a very complicated b ehavior b oth over time and wavelength, and it can hardly b e related to the exp ected reverb eration signal from the simple disk mo del. The profile evolution for some galaxies (NGC 4151, Mrk 6, 3C 390.3) can b e repro duced to larger or smaller extent with the two-comp onent mo del in which profile changes are due to changes in the relative strength of two variable comp onents with a fixed shap e. The double p eaked profile was often observed among the discussed ob jects. Profile decomp osition gives one comp onent that dominates in the central part of the profile, while the double p eaked comp onent dominates in the profile wings. However, the moving features of the profile shap es observed, e.g., in 3C 390.3, NGC 4151, and Arp 102B can b e a result of rotating redistribution of matter in the Keplerian disk. Acknow ledgements.The research was made in partly by the award UP 1-2549-CR-03 of the US Civilian Research and Development Foundation for the Indep endent States of the Former Soviet Union (CRDF) and by the Russian Foundation for Basic Research (RFBR) grant 06-02-16843.