Astronomy and Astrophysics – Astrophysics
Scientific paper
2003-05-21
Astron.Astrophys. 407 (2003) 791-822
Astronomy and Astrophysics
Astrophysics
35 pages, 17 figures, to appear in Astronomy and Astrophysics, full paper with high-resolution figures available at http://w
Scientific paper
10.1051/0004-6361:20030621-1
ISOCAM was used to perform a deep survey through three gravitationally lensing clusters of galaxies. Nearly seventy sq. arcmin were covered over the clusters A370, A2218 and A2390. We present maps and photometry at 6.7 & 14.3 microns, showing a total of 145 mid-IR sources and the associated source counts. The 15 micron counts reach the faintest level yet recorded. All sources have counterparts in the optical or near-IR. Models of the clusters were used to correct for the effects of lensing, which increases the sensitivity of the survey. Seven of fifteen SCUBA sources were detected at 15 microns. Five have redshift between 0.23 & 2.8, with a median of 0.9. The field sources were counted to a lensing-corrected sensitivity of 30 microJy at 15 microns, and 14 microJy at 7 microns. The counts, corrected for completeness, contamination by cluster sources and lensing, confirm and extend findings of an excess by a factor of ten in the 15 micron population with respect to source models with no evolution. Source redshifts are mostly between 0.4 and 1.5. For the counts at 7 microns, integrating from 14 microJy to 460 microJy, we resolve 0.49+/-0.2 nW.m^(-2).sr^(-1) of the infrared background light (IBL) into discrete sources. At 15 microns we include the counts from other ISOCAM surveys to integrate from 30 microJy to 50 mJy, two to three times deeper than unlensed surveys, to resolve 2.7+/-0.62 nW.m^(-2).sr^(-1) of the IBL. These values are 10% and 55%, respectively, of the upper limit to the IBL, derived from photon-photon pair production of the TeV gamma rays from BL-Lac sources on the IBL photons. However, recent detections of TeV gamma rays from the z=0.129 BL Lac H1426+428 suggest that the 15 micron background reported implies substantial absorption of TeV photons from that source.
Altieri Bruno
Biviano Andrea
Delaney Matt
Elbaz David
Kessler Martin F.
No associations
LandOfFree
An ISOCAM survey through gravitationally lensing galaxy clusters 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 An ISOCAM survey through gravitationally lensing galaxy clusters, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and An ISOCAM survey through gravitationally lensing galaxy clusters will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-343466