Extremely Red Objects in The Lockman Hole

G. Wilson, J.-S. Huang, P. G. Perez-Gonzalez, E. Egami, R. J. Ivison, J. R. Rigby, A. Alonso-Herrero, P. Barmby, H. Dole, G. G. Fazio, E. Le Floc'h, C. Papovich, D. Rigopoulou, L. Bai, C. W. Engelbracht, D. Frayer, K. D. Gordon, D. C. Hines, K. A. Misselt, S. Miyazaki, J. E. Morrison, G. H. Rieke, M. J. Rieke, J. Surace 2004, ApJS, 154, 107

We investigate Extremely Red Objects (EROs) using near- and mid-infrared observations in five passbands (3.6 to 24 micron) obtained from the Spitzer Space Telescope, and deep ground-based R and K imaging. The great sensitivity of the IRAC camera allows us to detect 64 EROs in only 12 minutes of IRAC exposure time, by means of an R-[3.6] color cut (analogous to the traditional red R-K cut). A pure infrared K-[3.6] red cut detects a somewhat different population and may be more effective at selecting z > 1.3 EROs. We find 17% of all galaxies detected by IRAC at 3.6 or 4.5 micron to be EROs. These percentages rise to about 40% at 5.8 micron, and about 60% at 8.0 micron. We utilize the spectral bump at 1.6 micron to divide the EROs into broad redshift slices using only near-infrared colors (2.2/3.6/4.5 micron). We conclude that two-thirds of all EROs lie at redshift z > 1.3. Detections at 24 micron imply that at least 11% of 0.6 < z < 1.3 EROs and at least 22% of z > 1.3 EROs are dusty star-forming galaxies.

[XXX/astro-ph Preprint] [ADS Entry]

ADS Citation Query
# citations = 18
average # citations/year = 3.00 (# years = 6)
# citations vs. year [year=citations]
[2009=1] [2008=4] [2007=2] [2006=4] [2005=5] [2004=2]
[determined from ADS on 10 Sep 2010]