NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-08-25 T07:36:36 PDT
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For refcode 2016ApJ...821...33R:
Retrieve 102 NED objects in this reference.
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Copyright by American Astronomical Society. Reproduced by permission
2016ApJ...821...33R Broad Hbeta Emission-line Variability in a Sample of 102 Local Active Galaxies Runco, Jordan N.; Cosens, Maren; Bennert, Vardha N.; Scott, Bryan; Komossa, S.; Malkan, Matthew A.; Lazarova, Mariana S.; Auger, Matthew W.; Treu, Tommaso; Park, Daeseong Abstract. A sample of 102 local (0.02 <= z <= 0.1) Seyfert galaxies with black hole masses M_BH_ > 10^7^M_sun_ was selected from the Sloan Digital Sky Survey (SDSS) and observed using the Keck 10 m telescope to study the scaling relations between M_BH_ and host galaxy properties. We study profile changes of the broad Hbeta emission line within the three to nine year time frame between the two sets of spectra. The variability of the broad Hbeta emission line is of particular interest, not only because it is used to estimate M_BH_, but also because its strength and width are used to classify Seyfert galaxies into different types. At least some form of broad-line variability (in either width or flux) is observed in the majority (~66%) of the objects, resulting in a Seyfert-type change for ~38% of the objects, likely driven by variable accretion and/or obscuration. The broad Hbeta line virtually disappears in 3/102 (~3%) extreme cases. We discuss potential causes for these changing look active galactic nuclei. While similar dramatic transitions have previously been reported in the literature, either on a case-by-case basis or in larger samples focusing on quasars at higher redshifts, our study provides statistical information on the frequency of Hbeta line variability in a sample of low-redshift Seyfert galaxies. Key words: accretion, accretion disks, galaxies: active, galaxies: evolution, galaxies: Seyfert, galaxies: statistics
Retrieve 102 NED objects in this reference.
Please click here for ADS abstract

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