Diagnosing DASH: A Catalog of Structural Properties for the COSMOS-DASH Survey
Sam E. Cutler, Katherine E. Whitaker, Lamiya Mowla, Gabriel Brammer, Arjen van der Wel, Danilo Marchesini, Pieter van Dokkum, Ivelina Momcheva, Mimi Song, Mohammad Akhshik, Erica J. Nelson, Rachel Bezanson, Marijn Franx, Mariska Kriek, Daniel Lange-Vagle, Joel Leja, John MacKenty, Adam Muzzin, Heath Shipley
Abstract
Abstract We present the H 160 morphological catalogs for the COSMOS-DASH survey, the largest area near-IR survey using HST-WFC3 to date. Utilizing the “Drift And SHift” observing technique for HST-WFC3 imaging, the COSMOS-DASH survey imaged approximately 0.5 deg 2 of the UltraVISTA deep stripes (0.7 deg 2 , when combined with archival data). Global structural parameters are measured for 51,586 galaxies within COSMOS-DASH using GALFIT (excluding the CANDELS area) with detection using a deep multi-band HST image. We recover consistent results with those from the deeper 3D-HST morphological catalogs, finding that, in general, sizes and Sérsic indices of typical galaxies are accurate to limiting magnitudes of H 160 < 23 and H 160 < 22 ABmag, respectively. In size-mass parameter space, galaxies in COSMOS-DASH demonstrate robust morphological measurements out to z ∼ 2 and down to <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>⋆</mml:mo> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy="true">/</mml:mo> </mml:mrow> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>⊙</mml:mo> </mml:mrow> </mml:msub> <mml:mo stretchy="false">)</mml:mo> <mml:mo>∼</mml:mo> <mml:mn>9</mml:mn> </mml:math> . With the advantage of the larger area of COSMOS-DASH, we measure a flattening of the quiescent size-mass relation below <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>⋆</mml:mo> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy="true">/</mml:mo> </mml:mrow> <mml:msub> <mml:mrow> <mml:mi>M</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>⊙</mml:mo> </mml:mrow> </mml:msub> <mml:mo stretchy="false">)</mml:mo> <mml:mo>∼</mml:mo> <mml:mn>10.5</mml:mn> </mml:math> that persists out to z ∼ 2. We show that environment is not the primary driver of this flattening, at least out to z = 1.2, whereas internal physical processes may instead govern the structural evolution.