ADS Astronomy Abstract Service

Title:		The optical and near-infrared colors of galaxies, 1: The photometric data
Authors:		BERSHADY, MATTHEW A.; HERELD, MARK; KRON, RICHARD G.; KOO, DAVID C.; MUNN, JEFFREY A.; MAJEWSKI, STEVEN R.
Affiliation:		AAUniv. of Chicago, Chicago, IL, US ABUniv. of Chicago, Chicago, IL, US ACFermi National Accelerator Lab., Batavia, IL, US ADUniv. of California, Santa Cruz, CA, US AEUniv. of Chicago, Williams Bay, WI, US AFCarnegie Inst. of Washington, Pasadena, CA, US
Journal:		The Astronomical Journal, vol. 108, no. 3, p. 870-895
Publication Date:		09/1994
Category:		Astronomy
Origin:		STI
NASA/STI Keywords:		ASTRONOMICAL PHOTOGRAPHY, ASTRONOMICAL PHOTOMETRY, COLOR, GALAXIES, IMAGE ANALYSIS, IMAGE PROCESSING, IMAGING TECHNIQUES, INFRARED ASTRONOMY, INFRARED PHOTOMETRY, INFRARED SPECTROSCOPY, NEAR INFRARED RADIATION, RED SHIFT, SPECTRAL ENERGY DISTRIBUTION, APERTURES, CALIBRATING, GRAPHS (CHARTS), PHOTOGRAPHIC PLATES, SAMPLES, TABLES (DATA)
Bibliographic Code:		1994AJ....108..870B

Abstract

We present optical and near-infrared photometry and spectroscopic redshifts of a well defined sample of 171 field galaxies selected from three high galactic latitude fields. This data set forms the basis for subsequent studies to characterize the trends, dispersion, and evolution of rest-frame colors and image structure. A subset of 143 galaxies constitutes a magnitude-limited sample to B approx. 19.9-20.75 (depending on field), with a median redshift of 0.14, and a maximum redshift of 0.54. This subset is statistically representative in its sampling of the apparent color distribution of galaxies. Thirty six galaxies were selected to have the reddest red-optical colors in two redshift intervals between 0.2 less than z less than 0.3. Photometric passbands are similar to U, B, V, I, and K, and sample galaxy spectral energy distributions between 0.37 and 2.2 micrometers in the observed frame, or down to 0.26 micrometers in the rest frame for the most distant galaxies. B and K images of the entire sample are assembled to form the first optical and near-infrared atlas of a statistically-representative sample of field galaxies. We discuss techniques for faint field-galaxy photometry, including a working definition of a total magnitude, and a method for matching magnitudes in different passbands and different seeing conditions to ensure reliable, integrated colors. Photographic saturation, which substantially affects the brightest 12% of our sample in the optical bands, is corrected with a model employing measured plate-density distributions for each galaxy, calibrated via similar measurements for stars as a function of known saturation level. Both the relative and absolute calibration of our photometry are demonstrated.