Structural Parameters of Galaxies in CANDELS
Kartaltepe, J. S.; Barden, M.; Ferguson, H. C.; Koekemoer, A. M.; Rix, H. -W.; Faber, S. M.; van der Wel, A.; Bell, E. F.; Grogin, N. A.; Galametz, A.; Hartley, W.; Peng, Chien Y.; Guo, Yicheng; Kocevski, D. D.; Lotz, J.; Mozena, M.; McGrath, E. J.; McIntosh, D. H.; Cheung, E.; Häussler, B.; Chang, Yu-Yen; Peth, M. A.
Germany, United States, United Kingdom, Austria, Italy
Abstract
We present global structural parameter measurements of 109,533 unique, H F160W-selected objects from the CANDELS multi-cycle treasury program. Sérsic model fits for these objects are produced with GALFIT in all available near-infrared filters (H F160W, J F125W and, for a subset, Y F105W). The parameters of the best-fitting Sérsic models (total magnitude, half-light radius, Sérsic index, axis ratio, and position angle) are made public, along with newly constructed point-spread functions for each field and filter. Random uncertainties in the measured parameters are estimated for each individual object based on a comparison between multiple, independent measurements of the same set of objects. To quantify systematic uncertainties, we create a mosaic with simulated galaxy images with a realistic distribution of input parameters and then process and analyze the mosaic in an identical manner as the real data. We find that accurate and precise measurements—to 10% or better—of all structural parameters can typically be obtained for galaxies with H F160W < 23, with comparable fidelity for basic size and shape measurements for galaxies to H F160W ~ 24.5.