Characterization of Extragalactic 24micron Sources in the Spitzer First Look Survey

Details Characterization of Extragalactic 24micron Sources in the Spitzer First Look Survey Characterization of Extragalactic 24micron Sources in the Spitzer First Look Survey

2004-05-31

arxiv.org/abs/astro-ph/0405637v1

Astronomy and Astrophysics

Astrophysics

Accepted for publication in ApJ (Spitzer Special Issue)

Scientific paper

10.1086/422824

In this Letter, we present the initial characterization of extragalactic 24um sources in the Spitzer First Look Survey (FLS) by examining their counterparts at 8um and R-band. The color-color diagram of 24-to-8 vs. 24-to-0.7um is populated with 18,734 sources brighter than the 3sigma flux limit of 110uJy, over an area of 3.7sq.degrees. The 24-to-0.7um colors of these sources span almost 4 orders of magnitudes, while the 24-to-8um colors distribute at least over 2 orders of magnitudes. In addition to identifying ~30% of the total sample with infrared quiescent, mostly low redshift galaxies, we also found that: (1) 23% of the 24um sources (~1200/sq.degrees) have very red 24-to-8 and 24-to-0.7 colors and are probably infrared luminous starbursts with L(IR)>3x10^(11)Lsun at z>1. In particular, 13% of the sample (660/sq.degrees) are 24um detected only, with no detectable emission in either 8um or R-band. These sources are the candidates for being ULIRGs at z>2. (2) 2% of the sample (85/sq.degrees) have colors similar to dust reddened AGNs, like Mrk231 at z~0.6-3. (3) We anticipate that some of these sources with extremely red colors may be new types of sources, since they can not be modelled with any familiar type of spectral energy distribution. We find that 17% of the 24um sources have no detectable optical counterparts brighter than R limit of 25.5mag. Optical spectroscopy of these optical extremely faint 24um sources would be very difficult, and mid-infrared spectroscopy from the Spitzer would be critical for understanding their physical nature (Abridged).

Affiliated with

Also associated with

No associations

Rating

Characterization of Extragalactic 24micron Sources in the Spitzer First Look Survey 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 Characterization of Extragalactic 24micron Sources in the Spitzer First Look Survey, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Characterization of Extragalactic 24micron Sources in the Spitzer First Look Survey will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-368367