Can Chandra resolve the remaining cosmic X-ray background?

Details Can Chandra resolve the remaining cosmic X-ray background? Can Chandra resolve the remaining cosmic X-ray background?

2007-06-21

arxiv.org/abs/0706.3089v3

Astrophys.J. 671 (2007) 1523-1531

Astronomy and Astrophysics

Astrophysics

9 emulateapj pages, 8 figures, v3: matches version to appear in ApJ (note correction to approximation of Poisson errors)

Scientific paper

10.1086/522918

The deepest extragalactic X-ray observation, the 2 Ms Chandra Deep Field North (CDF-N), resolves ~80% of the total extragalactic cosmic X-ray background (CXB) in the 1-2 keV band. Recent work has shown that 70% of the remaining CXB flux is associated with sources detected by the Hubble Space Telescope (HST). This paper uses the existing CDF-N data to constrain the X-ray flux distribution of these X-ray undetected HST sources, by comparing the number of 0.5-2 keV X-ray counts at the HST positions to those expected for model flux distributions. In the simple case where all the undetected HST X-ray sources have the same 0.5-2 keV flux, the data are best fit by 1.5-3 counts per source in 2 Ms, compared to a detection limit (at 10% completeness) of 9 counts. Assuming a more realistic power-law logN-logS distribution [N(>S) S^-alpha], the data favor a relatively steep flux distribution, with alpha=1.1^+0.5_-0.3 (limits are 99% confidence). This slope is very similar to that previously found for faint normal and starburst galaxies in the CDF-N. These results suggest deeper Chandra observations will detect a new population of faint X-ray sources, but extremely deep exposures are needed to resolve the remainder of the soft CXB. In the most optimistic scenario, when the HST sources have the flattest allowed flux distribution and all the sources without HST counterparts are detected, observations 5 times more sensitive than the existing ones would resolve at most ~60% of the remaining soft CXB.

Affiliated with

Also associated with

No associations

Rating

Can Chandra resolve the remaining cosmic 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 Can Chandra resolve the remaining cosmic X-ray background?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Can Chandra resolve the remaining cosmic X-ray background? will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-192438