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Rashed, Y. E., Eckart, A., Valencia-S, M., Garcia-Marin, M., Busch, G., Zuther, J., Horrobin, M. and Zhou, H. (2015). Line and continuum variability in active galaxies. Mon. Not. Roy. Astron. Soc., 454 (3). S. 2918 - 2946. OXFORD: OXFORD UNIV PRESS. ISSN 1365-2966

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Abstract

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 Delta L-line proportional to (Delta L-cont)(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.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Rashed, Y. E. UNSPECIFIED UNSPECIFIED UNSPECIFIED Eckart, A. UNSPECIFIED UNSPECIFIED UNSPECIFIED Valencia-S, M. UNSPECIFIED UNSPECIFIED UNSPECIFIED Garcia-Marin, M. UNSPECIFIED UNSPECIFIED UNSPECIFIED Busch, G. UNSPECIFIED UNSPECIFIED UNSPECIFIED Zuther, J. UNSPECIFIED UNSPECIFIED UNSPECIFIED Horrobin, M. UNSPECIFIED UNSPECIFIED UNSPECIFIED Zhou, H. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-383753
DOI:	10.1093/mnras/stv2066
Journal or Publication Title:	Mon. Not. Roy. Astron. Soc.
Volume:	454
Number:	3
Page Range:	S. 2918 - 2946
Date:	2015
Publisher:	OXFORD UNIV PRESS
Place of Publication:	OXFORD
ISSN:	1365-2966
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language DIGITAL SKY SURVEY; QUASI-STELLAR OBJECTS; 7TH DATA RELEASE; SPECTROGRAPH WAVELENGTH CALIBRATION; RESOLVED OPTICAL SPECTROSCOPY; SERENDIPITOUS SOURCE CATALOG; RESOLUTION SPECTRAL ATLAS; COLOR-SELECTED QUASARS; SEYFERT 1 GALAXIES; SDSS STRIPE 82 Multiple languages Astronomy & Astrophysics Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/38375