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The Las Campanas Infrared Survey. III. TheH‐Band Imaging Survey and the Near‐Infrared and Optical Photometric Catalogs

Authors :
Patrick J. McCarthy
Richard G. McMahon
Martin G. Beckett
Ofer Lahav
C. N. Sabbey
Richard S. Ellis
Augustus Oemler
Ronald O. Marzke
James R. Lewis
Roberto Abraham
Raymond G. Carlberg
Andrew E. Firth
Rachel S. Somerville
John Wilson
S. E. Persson
Hsiao-Wen Chen
Craig D. Mackay
D. C. Murphy
Paul Martini
Source :
The Astrophysical Journal. 570:54-74
Publication Year :
2002
Publisher :
American Astronomical Society, 2002.

Abstract

(Abridged) The Las Campanas Infrared Survey, based on broad-band optical and near-infrared photometry, is designed to robustly identify a statistically significant and representative sample of evolved galaxies at redshifts z>1. We have completed an H-band imaging survey over 1.1 square degrees of sky in six separate fields. The average 5 sigma detection limit in a four arcsecond diameter aperture is H ~ 20. Here we describe the design of the survey, the observation strategies, data reduction techniques, and object identification procedures. We present sample near-infrared and optical photometric catalogs for objects identified in two survey fields. We perform object detection in all bandpasses and identify ~ 54,000 galaxies over 1,408 square arcminutes of sky in the two fields. Of these galaxies, ~ 14,000 are detected in the H-band and ~ 2,000 have the colors of evolved galaxies, I - H >3, at z > 1. We find that (1) the differential number counts N(m) for the H-band detected objects has a slope of 0.44 at H < 19 and 0.27 for H > 19. In addition, we find that (2) the differential number counts for the H detected red objects has a slope of 0.85 at H < 20 and 0.32 at H > 20, with a mean surface density ~ 3,000 degree^{-2} mag^{-1} at H=20. Finally, we find that (3) galaxies with red optical to near-IR colors (I-H > 3) constitute ~ 20% of the H detected galaxies at H ~ 21, but only 2% at H = 19. We show that red galaxies are strongly clustered, which results in a strong field to field variation in their surface density. Comparisons of observations and predictions based on various formation scenarios indicate that these red galaxies are consistent with mildly evolving early-type galaxies at z ~ 1, although with a significant amount of on-going star formation as indicated by the large scatter in their V-I colors.<br />48 pages, 13 figures, accepted for publication in the Astrophysical Journal

Details

ISSN :
15384357 and 0004637X
Volume :
570
Database :
OpenAIRE
Journal :
The Astrophysical Journal
Accession number :
edsair.doi.dedup.....1152fabc919c528e85710560a598e525
Full Text :
https://doi.org/10.1086/339426