NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-06-17 T18:31:23 PDT
Help | Comment | NED Home

For refcode 2007ApJ...662..205B:
Retrieve 1 NED object in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
2007ApJ...662..205B NGC 5548 in a Low-Luminosity State: Implications for the Broad-Line Region Misty C. Bentz, Kelly D. Denney, Edward M. Cackett, Matthias Dietrich, Jeffrey K. J. Fogel, Himel Ghosh, Keith D. Horne, Charles Kuehn, Takeo Minezaki, Christopher A. Onken, Bradley M. Peterson, Richard W. Pogge, Vladimir I. Pronik, Douglas O. Richstone, Sergey G. Sergeev, Marianne Vestergaard, Matthew G. Walker, and Yuzuru Yoshii Abstract. We describe results from a new ground-based monitoring campaign on NGC 5548, the best-studied reverberation-mapped AGN. We find that it was in the lowest luminosity state yet recorded during a monitoring program, namely L_5100_=4.7x10^42^ ergs s^-1^. We determine a rest-frame time lag between flux variations in the continuum and the H{beta} line of 6.3^+2.6^_-2.3_ days. Combining our measurements with those of previous campaigns, we determine a weighted black hole mass of M_BH_=6.54^+0.26^_-0.25_x10^7^M_sun_ based on all broad emission lines with suitable variability data. We confirm the previously discovered virial relationship between the time lag of emission lines relative to the continuum and the width of the emission lines in NGC 5548, which is the expected signature of a gravity-dominated broad-line region. Using this lowest luminosity state, we extend the range of the relationship between the luminosity and the time lag in NGC 5548 and measure a slope that is consistent with {alpha}=0.5, the naive expectation for the broad-line region for an assumed form of r is proportional to L^{alpha}^. This value is also consistent with the slope recently determined by Bentz et al. for the population of reverberation-mapped AGNs as a whole. Key words: Galaxies: Active, Galaxies: Nuclei, Galaxies: Seyfert
Retrieve 1 NED object in this reference.
Please click here for ADS abstract

Back to NED Home