STRUCTURAL PARAMETERS OF GALAXIES IN CANDELS

Abstract

We present global structural parameter measurements of 109,533 unique,\nH_F160W-selected objects from the CANDELS multi-cycle treasury program. Sersic\nmodel fits for these objects are produced with GALFIT in all available\nnear-infrared filters (H_F160W, J_F125W and, for a subset, Y_F105W). The\nparameters of the best-fitting Sersic models (total magnitude, half-light\nradius, Sersic index, axis ratio, and position angle) are made public, along\nwith newly constructed point spread functions for each field and filter. Random\nuncertainties in the measured parameters are estimated for each individual\nobject based on a comparison between multiple, independent measurements of the\nsame set of objects. To quantify systematic uncertainties we create a mosaic\nwith simulated galaxy images with a realistic distribution of input parameters\nand then process and analyze the mosaic in an identical manner as the real\ndata. We find that accurate and precise measurements -- to 10% or better -- of\nall structural parameters can typically be obtained for galaxies with H_F160W <\n23, with comparable fidelity for basic size and shape measurements for galaxies\nto H_F160W ~ 24.5.\n