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Steps toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei. X. Variability of Fairall 9 from Optical Data

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dc.contributor.author Santos-Lleo, M
dc.contributor.author Chatzichristou, E
dc.contributor.author de Oliveira, C. M
dc.contributor.author Winge, C
dc.contributor.author Alloin, D
dc.contributor.author Peterson, B. M
dc.contributor.author Rodriguez-Pascual, P. M
dc.contributor.author Stirpe, G. M
dc.contributor.author Beers, T
dc.contributor.author Bragaglia, A
dc.contributor.author Claeskens, J. F
dc.contributor.author Federspiel, M
dc.contributor.author Giannuzzo, E
dc.contributor.author Gregorio-Hetem, J
dc.contributor.author Mathys, G
dc.contributor.author Salamanca, I
dc.contributor.author Stein, P
dc.contributor.author Stenholm, B
dc.contributor.author Wilhelm, R
dc.contributor.author Zanin, C
dc.contributor.author Albrecht, P
dc.contributor.author Calderon, J
dc.contributor.author Caretta, C. A
dc.contributor.author Carranza, G
dc.contributor.author da Costa, R. D. D
dc.contributor.author Diaz, R
dc.contributor.author Dietrich, M
dc.contributor.author Dottori, H
dc.contributor.author Elizalde, F
dc.contributor.author Goldes, G
dc.contributor.author Ghosh, K. K
dc.contributor.author Maia, M. A. G
dc.contributor.author Paolantonio, S
dc.contributor.author de Oliveira Filho, R. I
dc.contributor.author Rodriguez-Ardila, A
dc.contributor.author Schmitt, H. R
dc.contributor.author Soundararajaperumal, S
dc.contributor.author de Souza, R. E
dc.contributor.author Willmer, C. N. A
dc.contributor.author Zheng, W
dc.date.accessioned 2008-08-22T05:41:47Z
dc.date.available 2008-08-22T05:41:47Z
dc.date.issued 1997-10
dc.identifier.citation Astrophysical Journal Supplement Series, Vol. 112, No. 2, pp. 271 - 283 en
dc.identifier.issn 0067-0049
dc.identifier.uri http://hdl.handle.net/2248/3235
dc.description.abstract The results of an optical monitoring campaign on the active nucleus in the luminous Seyfert 1 galaxy Fairall 9 are presented. This campaign was undertaken in parallel with ultraviolet spectroscopic monitoring with the IUE satellite which is described in a separate paper. The primary purpose of this program is to measure the response times (or "lags") of the emission lines to continuum variations and thus to extend the range in luminosity of active galactic nuclei (AGNs) for which such measurements have been made. The main conclusions of this work are as follows: 1. Continuum (at 5340 Angstroms) variations of amplitude ~12% are detected on timescales as short as ~20 days. These variations are much larger than the typical uncertainties in the measurements, which are of order ~2%. Over ~94 days, a factor of 2 change in the nuclear continuum was observed. 2. The optical continuum light curve resembles that of the UV continuum, showing two "events" of low-amplitude variations with a duration of ~70 days and with no measurable lag between the UV and optical continuum light curves. The UV data show a third larger amplitude event that occurred after the optical monitoring had terminated and unfortunately went unobserved in the optical. 3. The H beta emission-line flux also underwent significant, low-amplitude (>=20%) variations. Cross-correlation analysis reveals that H beta lags behind the UV continuum by about 23 days, a value much smaller than what was previously suggested by earlier variability studies. However, this small lag is consistent with the lags for the UV lines during this campaign in the sense that the H beta lag is approximately 50% larger than that of Ly alpha lambda 1216, as it has been found for lower luminosity AGNs. 4. The H beta difference profile produced by subtracting the low-state from the high-state data can be described as a two-component structure with blue and red components of similar width (~2500 km s-1) and that appear to vary in phase. en
dc.format.extent 810258 bytes
dc.format.mimetype application/pdf
dc.language.iso en en
dc.publisher American Astronomical Society en
dc.relation.uri http://www.journals.uchicago.edu/doi/abs/10.1086/313046 en
dc.subject Galaxies: Active en
dc.subject Galaxies: Individual Name: Fairall 9 en
dc.subject Galaxies: Nuclei en
dc.subject Galaxies: Seyfert en
dc.title Steps toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei. X. Variability of Fairall 9 from Optical Data en
dc.type Article en

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