arXiv Analytics

Sign in

arXiv:astro-ph/0405635AbstractReferencesReviewsResources

Extragalactic Source Counts at 24 Microns in the Spitzer First Look Survey

Francine R. Marleau, D. Fadda, L. J. Storrie-Lombardi, G. Helou, D. Makovoz, D. T. Frayer, L. Yan, P. N. Appleton, L. Armus, S. Chapman, P. I. Choi, F. Fang, I. Heinrichsen, M. Im, M. Lacy, D. Shupe, B. T. Soifer, G. Squires, J. Surace, H. I. Teplitz, G. Wilson

Published 2004-05-31Version 1

We present the Spitzer MIPS 24 micron source counts in the Extragalactic First Look Survey main, verification and ELAIS-N1 fields. Spitzer's increased sensitivity and efficiency in large areal coverage over previous infrared telescopes, coupled with the enhanced sensitivity of the 24 micron band to sources at intermediate redshift, dramatically improve the quality and statistics of number counts in the mid-infrared. The First Look Survey observations cover areas of, respectively, 4.4, 0.26 and 0.015 sq.deg. and reach 3-sigma depths of 0.11, 0.08 and 0.03 mJy. The extragalactic counts derived for each survey agree remarkably well. The counts can be fitted by a super-Euclidean power law of index alpha=-2.9 from 0.2 to 0.9 mJy, with a flattening of the counts at fluxes fainter than 0.2 mJy. Comparison with infrared galaxy evolution models reveals a peak's displacement in the 24 micron counts. This is probably due to the detection of a new population of galaxies with redshift between 1 and 2, previously unseen in the 15 micron deep counts.

Comments: Accepted for publication in special Spitzer ApJS issue, 4 pages
Categories: astro-ph
Related articles: Most relevant | Search more
arXiv:astro-ph/0405637 (Published 2004-05-31)
Characterization of Extragalactic 24micron Sources in the Spitzer First Look Survey
Lin Yan et al.
arXiv:astro-ph/0701040 (Published 2007-01-03)
The Role of Galaxy Interactions and Mergers in Star Formation at z<1.3: Mid-Infrared Properties in the Spitzer First Look Survey
C. R. Bridge et al.
arXiv:astro-ph/0411451 (Published 2004-11-16, updated 2004-11-26)
Extragalactic Source Counts in the Spitzer 24-micron Band: What Do We Expect From ISOCAM 15-micron Data and Models?