Probing the Absorption Structures in Seyfert Galaxies with X-ray Spectroscopy

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

The paradigm of the unified model for Seyfert galaxies has had many successes in explaining the range of phenomena observed in active galaxies. However, the structures invoked in this scenario have been difficult to observe due to their limited sizes and due to contaminating flux from other regions. As a result, some of these structures, notably the putative obscuring torus, are poorly constrained. The difficulty in isolating the emission from the central regions can be mitigated (but not eliminated!) by focusing upon high-energy radiation, which is dominated by direct and reprocessed radiation from the nuclear region. We have drawn upon the large number of X-ray spectra available in the ASCA archive in order to study the distribution of properties in a large sample of high-energy observations. Furthermore, by uniformly processing the data ourselves, we minimize systematic effects. One asset of X-rays is that they provide a sensitive probe of absorbers in the line of sight toward the central region, because photoelectric absorption cuts off the continuum at low energies. In the ASCA bandpass column densities of ~1021-23 cm-2 can be measured. This is an interesting range of densities because it allows us to distinguish between absorption in a torus or possibly a warped accretion disk (where column densities are expected to be high) and absorption taking place at larger scales in the host galaxy (where column densities are expected to be closer to Galactic values of 1020-21 cm-2). This data is then compared to data from other wavebands. Published radio studies (e.g.: Nagar & Wilson 1999, Kinney et al. 2000) have put constraints on the orientations of the accretion systems in Seyfert galaxies. We combine these and the X-ray measurements for the ~50 sources in these studies which have ASCA data in order to constrain the various possible absorption structures and test the unification scenario.

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

Probing the Absorption Structures in Seyfert Galaxies with X-ray Spectroscopy 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 Probing the Absorption Structures in Seyfert Galaxies with X-ray Spectroscopy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Probing the Absorption Structures in Seyfert Galaxies with X-ray Spectroscopy will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1231126

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