Ultra deep AKARI observations of Abell 2218: resolving the 15 um extragalactic background light
Abstract
We present extragalactic number counts and a lower limit estimate for the cosmic infrared background at 15 um from AKARI ultra deep mapping of the gravitational lensing cluster Abell 2218. This data is the deepest taken by any facility at this wavelength, and uniquely samples the normal galaxy population. We have de-blended our sources, to resolve photometric confusion, and de-lensed our photometry to probe beyond AKARI's blank-field sensitivity. We estimate a de-blended 5 sigma sensitivity of 28.7 uJy. The resulting 15 um galaxy number counts are a factor of three fainter than previous results, extending to a depth of ~ 0.01 mJy and providing a stronger lower limit constraint on the cosmic infrared background at 15 um of 1.9 +/- 0.5 nW m^-2 sr^-1.
Keywords
Cite
@article{arxiv.1005.1069,
title = {Ultra deep AKARI observations of Abell 2218: resolving the 15 um extragalactic background light},
author = {R. Hopwood and S. Serjeant and M. Negrello and C. Pearson and E. Egami and M. Im and J. -P. Kneib and J. Ko and H. M. Lee and M. G. Lee and H. Matsuhara and T. Nakagawa and I. Smail and T. Takagi},
journal= {arXiv preprint arXiv:1005.1069},
year = {2010}
}
Comments
Published in ApJ Letters; column added to table 1 and final column amended, plus minor corrections to match published version