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Hierarchical Formation in Action: Characterizing Accelerated Galaxy Evolution in Compact Groups Using Whole-Sky WISE Data

Zucker, Catherine and Walker, Lisa May and Johnson, Kelsey and Gallagher, Sarah and Alatalo, Katherine and Tzanavaris, Panayiotis (2016) Hierarchical Formation in Action: Characterizing Accelerated Galaxy Evolution in Compact Groups Using Whole-Sky WISE Data. Astrophysical Journal, 821 (2). Art. No. 113. ISSN 0004-637X.

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Compact groups provide an environment to study the growth of galaxies amid multiple prolonged interactions. With their dense galaxy concentrations and relatively low velocity dispersions, compact groups mimic the conditions of hierarchical galaxy assembly. Compact group galaxies are known to show a bimodality in Spitzer IRAC infrared color space: galaxies are preferentially either quiescent with low specific star formation rates (SSFRs) or prolifically forming stars—galaxies with moderate levels of specific star formation are rare. Previous Spitzer IRAC studies identifying this "canyon" have been limited by small number statistics. We utilize whole-sky Wide-field Infrared Survey Explorer (WISE) data to study 163 compact groups, thereby tripling our previous sample and including more galaxies with intermediate mid-IR colors indicative of moderate SSFRs. We define a distinct WISE mid-IR color space (log[^(f12)_(f4.6)] versus log[^(f22)_(f3.4)]) that we use to identify canyon galaxies from the larger sample. We confirm that compact group galaxies show a bimodal distribution in the mid-infrared and identify 37 canyon galaxies with reliable photometry and intermediate mid-IR colors. Morphologically, we find that the canyon harbors a large population of both Sa–Sbc and E/S0 type galaxies, and that they fall on the optical red sequence rather than the green valley. Finally, we provide a catalog of WISE photometry for 567 of 652 galaxies selected from the sample of 163 compact groups.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Johnson, Kelsey0000-0001-8348-2671
Alatalo, Katherine0000-0002-4261-2326
Tzanavaris, Panayiotis0000-0001-5737-5055
Additional Information:© 2016. The American Astronomical Society. Received 2015 August 9; accepted 2016 March 3; published 2016 April 20. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. Funding for the Sloan Digital Sky Survey IV has been provided by the Alfred P. Sloan Foundation, the U.S. Department of Energy Office of Science, and the Participating Institutions. SDSS-IV acknowledges support and resources from the Center for High-Performance Computing at the University of Utah. The SDSS Web site is C.S.Z. would like to sincerely thank the anonymous referee for their thorough feedback throughout the review process. She would also like to thank the Virginia Space Grant Consortium and the University of Virginia College of Arts and Sciences for support. S.C.G. thanks the Natural Sciences and Engineering Research Council of Canada for support.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
Alfred P. Sloan FoundationUNSPECIFIED
Department of Energy (DOE)UNSPECIFIED
University of UtahUNSPECIFIED
Virginia Space Grant ConsortiumUNSPECIFIED
University of VirginiaUNSPECIFIED
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
Subject Keywords:galaxies: evolution; galaxies: groups: general; galaxies: interactions
Issue or Number:2
Record Number:CaltechAUTHORS:20160623-104838138
Persistent URL:
Official Citation:Catherine Zucker et al 2016 ApJ 821 113
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:68633
Deposited By: Ruth Sustaita
Deposited On:23 Jun 2016 22:06
Last Modified:09 Mar 2020 13:19

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