Mon. Not. R. Astron. Soc., 454, 2918-2945 (2015/December-2)
Line and continuum variability in active galaxies.
RASHED Y.E., ECKART A., VALENCIA-S. M., GARCIA-MARIN M., BUSCH G., ZUTHER J., HORROBIN M. and ZHOU H.
Abstract (from CDS):
We compared optical spectroscopic and photometric data for 18 active galactic nuclei (AGN) galaxies over two to three epochs, with time intervals of typically 5 to 10 yr. We used the multi-object double spectrograph (MODS) at the Large Binocular Telescope (LBT) and compared the spectra with data taken from the SDSS data base and the literature. We found variations in the forbidden oxygen lines as well as in the hydrogen recombination lines of these sources. For four of the sources we found that, within the calibration uncertainties, the variations in continuum and line spectra of the sources are very small. We argue that it is mainly the difference in black hole mass between the samples that is responsible for the different degree of continuum variability. In addition, we found that for an otherwise constant accretion rate the total line variability (dominated by the narrow line contributions) reverberates in a similar way to the continuum variability with a dependence ΔLline ∝ (ΔLcont)3/2. Because this dependence is predominantly expressed in the narrow line emission, the implication is that the part of the source that dominates the luminosity in the narrow line region must be very compact, with a diameter of the order of at least 10 light-years. A comparison with data from the literature shows that these findings describe the variability characteristics of a total of 61 broad and narrow line sources.
© 2015 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society (2015)
Part 6.1.1: J0002 is a probable misprint for J0802 (SDSS J080248.19+551328.9). Reference stars from Table 4 are not in SIMBAD.
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