ASCA spectral constraints on an AGN synthesis model for the XRB

Mathematics – Logic

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

4

Scientific paper

We place strong spectral constraints on an AGN synthesis model for the extragalactic X-ray background (XRB). It is strongly believed that the XRB is nearly entirely composed of unresolved discrete sources, with a major contribution being due to AGN . Here, we use the unified AGN model of Antonucci to construct spectral models for the XRB. The primary adjustable parameters of these models are photon spectral index of the sources, column density for Seyfert 2 sources, ratio of Seyfert 2's to Seyfert 1's, their luminosity evolution, and the local volume emissivity. The existence of iron K line emission in AGN should produce spectral features in the XRB with some of these models. The magnitude of these features depend on the typical AGN X-ray spectrum as well as on the cosmological evolution of AGN. Several models predict structure in the 1-3 keV range where ASCA has high sensitivity and spectral resolution. We use the ASCA XRB data from deep survey fields to test these models. The ASCA data show no sharp spectral features in the XRB. The allowed parameter space for acceptable AGN synthesis models is small, but consistent with independently derived AGN data. We find that the equivalent width of the iron K line from the typical AGN must be less than 320 eV. We can put lower limits on the AGN luminosity evolution index of about 2.5. Applying independently derived X-ray volume emissivity results and AGN spectral indices as additional constraints, we can predict number ratios of Seyfert 2 to Seyfert 1 galaxies which are close to unity. We can also predict source counts in various bandpasses as a function of flux.

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

ASCA spectral constraints on an AGN synthesis model for the XRB 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 ASCA spectral constraints on an AGN synthesis model for the XRB, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and ASCA spectral constraints on an AGN synthesis model for the XRB will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1254304

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