Astronomy and Astrophysics – Astrophysics
Scientific paper
2001-01-18
Astronomy and Astrophysics
Astrophysics
9 pages, 11 figures, accepted for publication on A&A
Scientific paper
10.1051/0004-6361:20010132
The Seyfert 2 Galaxy NGC 7172 was observed twice by BeppoSAX narrow field instruments approximately one year apart. As found in previous observations, the source is variable on short time scales (hours) by a factor of $\sim$30%, confirming the presence of a type 1 nucleus at the center. A strong flux variability (by a factor of 2) on a longer time scale was observed between the two observations. Indeed, in November 1997, the lowest flux ever recorded was detected by BeppoSAX. The broad band spectra obtained with the BeppoSAX narrow field instruments show marginal evidence of a reflection component. This structure could explain the very flat spectra previously observed in the 2-10 keV band. An FeK$\alpha$ line was also detected in both observations. The line intensity appears to remain almost constant between the two observations even if the associated large errors cannot exclude some variability. In order to understand the problem of the origin of the line, data from previous observations, performed with other satellites, were also used. The scenario favored is one where the line is produced at a distance of approximatively 8 light years from the continuum source region, rather than having its origin in the accretion disk. In the framework of the standard unified models for AGN, this suggests that its origin is located in the molecular torus.
Bassani Loredana
Cappi Massimo
Cocco G. Di
Dadina Mauro
Guainazzi Matteo
No associations
LandOfFree
On the Origin of the FeK$α$ Line in the Seyfert 2 Galaxy NGC 7172 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 On the Origin of the FeK$α$ Line in the Seyfert 2 Galaxy NGC 7172, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and On the Origin of the FeK$α$ Line in the Seyfert 2 Galaxy NGC 7172 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-106781