NOAO >   Observing Info >   Approved Programs >   2009B-0321

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Proposal Information for 2009B-0321


PI: Helene M.L.G. Flohic, University of California, Irvine, hflohic@uci.edu
Address: Physics Department, 4129 Frederick Reines Hall, Irvine, CA 92697, USA

CoI: Micheal Eracleous, The Pennsylvania State University
CoI: Karen T. Lewis, Dickinson College

Title: Determining the Structure of an AGN Accretion Disk through Spectroscopic Monitoring of a Double-Peaked Emitter

Abstract: The accretion disks of Active Galactic Nuclei (AGNs) are the most likely source of the broad emission lines that are the hallmark of this class of object. A subset of AGNs display double-peaked broad emission line profiles, offering us a direct view of their accretion disks. Double-peaked line profile variability, commonly observed on a dynamical timescale or longer, likely traces structural changes in the accretion disk and has proven to be a very useful probe of the disk structure. However spectroscopic time series of double-peaked AGNs have been hard to obtain because they require decades of observations in order to sample a few dynamical timescales. We propose a weekly spectroscopic monitoring program of a double-peaked emitter with a lower mass black hole for 33 weeks, which will build a rich dataset in a fraction of the time that it took for the richest set currently available. With this dataset, we will test models for accretion disk instabilities that lead to short-term variations of the line profile and further our understanding of accretion disk structure in all AGNs. The conclusions will have far-reaching implications; for example, they will influence the use of scaling relations that yield the black hole mass from the widths of the broad-emission lines.


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NOAO >   Observing Info >   Approved Programs >   2009B-0321

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