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Steps Toward Determination of the Size and Structure of the Broad-Line Region in Active Galactic Nuclei XVI: A 13 Year Study of Spectral Variability in NGC 5548We present the final installment of an intensive 13 year study of variations of the optical continuum and broad H beta emission line in the Seyfert 1 galaxy NGC 5548. The database consists of 1530 optical continuum measurements and 1248 H beta measurements. The H beta variations follow the continuum variations closely, with a typical time delay of about 20 days. However, a year-by-year analysis shows that the magnitude of emission-line time delay is correlated with the mean continuum flux. We argue that the data are consistent with the simple model prediction between the size of the broad-line region and the ionizing luminosity, r is proportional to L(sup 1/2)(sub ion). Moreover, the apparently linear nature of the correlation between the H beta response time and the nonstellar optical continuum F(sub opt) arises as a consequence of the changing shape of the continuum as it varies, specifically F(sub opt) is proportional to F(sup 0.56)(sub UV).
Document ID
20040053265
Acquisition Source
Headquarters
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Peterson, B. M.
(Ohio State Univ. Columbus, OH, United States)
Berlind, P.
(Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Bertram, R.
(Ohio State Univ. Columbus, OH, United States)
Bischoff, K.
(Technische Univ. Goettingen, Germany)
Bochkarev, N. G.
(Sternberg Astronomical Inst. Moscow, USSR)
Burenkov, A. N.
(Sternberg Astronomical Inst. Moscow, USSR)
Calkins, M.
(Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Carrasco, L.
(Instituto Nacional de Astrofmsica, Optica y Electrsnica Puebla, Mexico)
Chavushyan, V. H.
(Instituto Nacional de Astrofmsica, Optica y Electrsnica Puebla, Mexico)
Date Acquired
August 21, 2013
Publication Date
December 10, 2002
Publication Information
Publication: The Astrophysical Journal
Publisher: American Astronomical Society
Volume: 581
Subject Category
Astrophysics
Funding Number(s)
CONTRACT_GRANT: INTAS-N96-0328
CONTRACT_GRANT: NAG5-8397
CONTRACT_GRANT: RBRF-N97-02-17625
CONTRACT_GRANT: RBRF-N00-02-16272a
CONTRACT_GRANT: NSF AST-99-87438
CONTRACT_GRANT: NAG5-3234
Distribution Limits
Public
Copyright
Other

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