NGC 5548 in a Low-Luminosity State: Implications for the Broad-Line Region

Details NGC 5548 in a Low-Luminosity State: Implications for the Broad-Line Region NGC 5548 in a Low-Luminosity State: Implications for the Broad-Line Region

2007-02-23

arxiv.org/abs/astro-ph/0702644v1

Astrophys.J.662:205-212,2007

Astronomy and Astrophysics

Astrophysics

24 pages, 3 tables, 7 figures, accepted for publication in ApJ

Scientific paper

10.1086/516724

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) = 4.7 x 10^42 ergs s^-1. We determine a rest-frame time lag between flux variations in the continuum and the Hbeta 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) x 10^7 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 ~ 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.

Affiliated with

Also associated with

No associations

Rating

NGC 5548 in a Low-Luminosity State: Implications for the Broad-Line Region does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with NGC 5548 in a Low-Luminosity State: Implications for the Broad-Line Region, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and NGC 5548 in a Low-Luminosity State: Implications for the Broad-Line Region will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-581725