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

Abstract

The Las Campanas Infrared Survey, based on broadband 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 deg 2 of sky in six separate fields. The average 5 detection limit in a 4 00 diameter aperture is H $ 20:8. 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. The optical images of the Hubble Deep Field-South region obtained from the literature reach 5 detection thresholds in a 4 00 diameter aperture of U $ 24:6, B $ 26:1, V $ 25:6, R $ 25:1, and I $ 24:2 mag. The optical images of the Chandra Deep Field-South region obtained from our own observations reach 5 detection thresholds in a 4 00 diameter aperture of V $ 26:8, R $ 26:2, I $ 25:3, and z 0 $ 23:7 mag. We perform object detection in all bandpasses and identify e 54,000 galaxies over 1408 arcmin 2 of sky in the two fields. Of these galaxies, $14,000 are detected in the H band and $2000 have the colors of evolved galaxies, IÀHe3, at ze1. We find that (1) the differential number counts NðmÞ for the H-band-detected objects has a slope of d log NðmÞ=dm ¼ 0:45 AE 0:01 mag À2 at Hd19 and 0:27 AE 0:01 mag À2 at He19, with a mean surface density %7200 deg À2 mag À1 at H ¼ 19. In addition, we find that (2) the differential number counts for the H-banddetected red objects has a very steep slope, d log Nðm; I À He3Þ=dm ¼ 0:84 AE 0:06 mag À2 at Hd20 and 0:32 AE 0:07 mag À2 at He20, with a mean surface density %3000 deg À2 mag À1 at H ¼ 20. Finally, we find that (3) galaxies with red optical to near-IR colors (IÀH > 3) constitute %20% of the H-band-detected galaxies at Hd21, but only %2% at Hd19. 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 ongoing star formation, as indicated by the large scatter in their VÀI colors.

Near-Infrared Galaxy Counts and Evolution From the Wide-Field Alhambra Survey

“…Our results, given in Table 4, show similar slopes for the J and H filter at the bright and faint ends. As can be seen in Tables 6 and 7 our result at the bright end are in good agreement with the bright-end slope values to H = 19 given in Martini (2001) and Chen et al (2002), and in the J filter with the results in Väisänen et al (2000) and Iovino et al (2005) …”

“…The Alhambra counts in the H band are in good correspondence with the published data by Martini (2001);Frith et al (2006) and with the bright part of the data from Moy et al (2003), after applying an offset of −0.215 mag. This offset was calculated following the −0.065 calibration difference among Las Campanas Infrared Survey (LCIRS; Chen et al 2002) reported in Moy et al (2003), and the systematic of −0.28 mag difference between LCIRS and 2MASS magnitudes reported in Frith et al (2006). However, the faint end (H > 20) of our data is significantly above the faint number count data from Yan et al (1998) and Metcalfe et al (2006), obtained from NICMOS observations.…”

The Great Observatories Origins Deep Survey

“…The comparison with the Las Campanas Infrared survey (LCIRS, Chen et al 2002) features a slight trend with magnitude in such a way that bright sources (H < ∼ 18) appear brighter in GOODS/ISAAC while faint sources appear to be unbiased or even slightly fainter than in the LCIRS. The (Olsen et al 2006), g) H-band observations of the CDF-S by Moy et al (2003), h) Las Campanas Infrared survey (Chen et al 2002), and, i) K20 survey (Cimatti et al 2002). The differences of magnitudes of sources as measured on the GOODS/ISAAC images and as given in the respective reference catalogs are displayed as a function of the measured GOODS/ISAAC magnitude in the AB system.…”

Spectrophotometric properties of galaxies at intermediate redshifts (z ~ 0.2–1.0)

“…The photometric magnitudes of the GDDS sub-sample were directly taken from the literature (Chen et al 2002): R band photometry of the NTT Deep field has been taken with the BTC camera on the Cerro Tololo Inter-American Observatory (CTIO) 4 m telescope, I band photometry of the NOAO-Cetus and SA22 fields have been taken with the CFH12k camera on the Canada France Hawaii Telescope (CFHT).…”