CANDELS Visual Classifications: Scheme, Data Release, and First Results
Abstract
We have undertaken an ambitious program to visually classify all galaxies in the five CANDELS fields down to H<24.5 involving the dedicated efforts of 65 individual classifiers. Once completed, we expect to have detailed morphological classifications for over 50,000 galaxies up to z<4 over all the fields. Here, we present our detailed visual classification scheme, which was designed to cover a wide range of CANDELS science goals. This scheme includes the basic Hubble sequence types, but also includes a detailed look at mergers and interactions, the clumpiness of galaxies, -corrections, and a variety of other structural properties. In this paper, we focus on the first field to be completed -- GOODS-S. The wide area coverage spanning the full field includes 7634 galaxies that have been classified by at least three different people. In the deep area of the field, 2534 galaxies have been classified by at least five different people at three different depths. With this paper, we release to the public all of the visual classifications in GOODS-S along with the GUI that we developed to classify galaxies. We find that the level of agreement among classifiers is good and depends on both the galaxy magnitude and the galaxy type, with disks showing the highest level of agreement and irregulars the lowest. A comparison of our classifications with the Sersic index and rest-frame colors shows a clear separation between disk and spheroid populations. Finally, we explore morphological k-corrections between the V-band and H-band observations and find that a small fraction (84 galaxies in total) are classified as being very different between these two bands. These galaxies typically have very clumpy and extended morphology or are very faint in the V-band.
Cite
@article{arxiv.1401.2455,
title = {CANDELS Visual Classifications: Scheme, Data Release, and First Results},
author = {Jeyhan S. Kartaltepe and Mark Mozena and Dale Kocevski and Daniel H. McIntosh and Jennifer Lotz and Eric F. Bell and Sandra Faber and Henry Ferguson and David Koo and Robert Bassett and Maksym Bernyk and Kirsten Blancato and Frederic Bournaud and Paolo Cassata and Marco Castellano and Edmond Cheung and Christopher J. Conselice and Darren Croton and Tomas Dahlen and Duilia F. de Mello and Laura DeGroot and Jennifer Donley and Javiera Guedes and Norman Grogin and Nimish Hathi and Matt Hilton and Brett Hollon and Hanae Inami and Susan Kassin and Anton Koekemoer and Caterina Lani and Nick Liu and Ray A. Lucas and Marie Martig and Elizabeth McGrath and Conor McPartland and Bahram Mobasher and Alice Morlock and Simon Mutch and Erin O'Leary and Mike Peth and Janine Pforr and Annalisa Pillepich and Gregory B. Poole and Zachary Rizer and David Rosario and Emmaris Soto and Amber Straughn and Olivia Telford and Ben Sunnquist and Benjamin Weiner and Stijn Wuyts},
journal= {arXiv preprint arXiv:1401.2455},
year = {2015}
}
Comments
15 pages, 14 figures, Accepted for publication in The Astrophysical Journal Supplement Series For access to data tables prior to publication contact jeyhan@astro.rit.edu