Hard X-ray emission from extragalactic IRAS 12um sources: constraints on the unified AGN model and the synthesis of the X-ray background

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Text: 31 pages (tex) + 3 tables (tex) + 6 figures (ps); uuencoded

Scientific paper

10.1086/176597

We analyze the $2-10$~keV X-ray emission of complete samples of AGN and galaxies selected at 12$\mu$m and recently compiled by Rush, Malkan \& Spinoglio (1993). As a necessary complement we also study the IR emissivity of the largest sample of hard X--ray selected AGN (Grossan 1992). Our purposes are to probe the unified scheme of active nuclei and to evaluate the local X--ray volume emissivity of low luminosity and `hidden' AGN. We confirm that X-ray emission is basically restricted to AGN, Seyfert 1's being much more powerful emitters than Seyfert 2's. We find no signal of X-ray emission for the remaining galaxies selected at $12\mu$m, not even for those having a flat far-infrared spectrum, which would be prime candidates to host hidden AGN. Our result on the local volume emissivity of the Seyfert 1's is fully consistent with those derived from studies of the hard X--ray luminosity function. However the 95$\%$ upper limits to the local emissivity we derive for the Seyfert 2 class and for the most likely `hidden' AGN candidates, severely constrain (and in some cases exclude) models of the X--ray background based on the unified Seyfert scheme. We also find that less than $\sim20$\% of Seyfert 1-like AGN and less than $\sim 50$\% of Seyfert 2-like AGN can be `hidden' in the non-Seyfert galaxy samples assuming that the X-ray to 12$\mu$m flux ratios measured in the 12$\mu$m selected samples can be considered typical for these classes of objects. In this case, the number ratio of Seyfert 2 to Seyfert 1 galaxies ranges from 1 to 2.

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

Hard X-ray emission from extragalactic IRAS 12um sources: constraints on the unified AGN model and the synthesis of the X-ray background 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 Hard X-ray emission from extragalactic IRAS 12um sources: constraints on the unified AGN model and the synthesis of the X-ray background, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hard X-ray emission from extragalactic IRAS 12um sources: constraints on the unified AGN model and the synthesis of the X-ray background will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-285317

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