Variations of geometrical and physical characteristics of innermost regions of active galactic nuclei on time-scale of years

Physics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

1

Scientific paper

Several examples of observational evidences of variations of geometrical and physical characteristics of the innermost regions of Active Galactic Nuclei on the time-scale of years are given. The 15 year long intensive monitoring of NGC 5548 clearly shows significant variations of broad line region (BLR) size on a time scale 6 to 26 days. An analysis of long-term (1984-2003) UBV variations of NGC 4151 shows that the slow changes in the optical continuum are connected with accretion discs (AD) formation and dissipation: during the 1984-1989 deep minimum the former AD is suggested to totally disappear and a new AD to begin to form since 1988-1989, reaching its maximal brightness in 1996. At the same time the fast variations of the continuum are due to flares in AD. For 3C390.3, there is observational evidence of connection between variations in UV and optical continua and radio-jets inner structure. We may figured out, that during the nucleus maximal brightness periods most of the continuum variable radiation is emitted from the jet (˜0.4 pc from the nucleus) and ionizes the surrounding gas, creating a BLR that mainly determines in the broad line emission. During the brightness minima the jet contribution to the ionizing continuum is decreasing and the main broad line emission comes from the "classical" BLR (AD and the surrounding gas). Such a scenario explains two maxima (˜30d and ˜100d) found in the cross-correlation function describing the time-lag of broad line variations relatively to continuum on the base of the results of 3C390.3 optical monitoring in1996-2001.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Variations of geometrical and physical characteristics of innermost regions of active galactic nuclei on time-scale of years 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 Variations of geometrical and physical characteristics of innermost regions of active galactic nuclei on time-scale of years, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Variations of geometrical and physical characteristics of innermost regions of active galactic nuclei on time-scale of years will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1082687

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.