HIERARCHICAL FORMATION IN ACTION: CHARACTERIZING ACCELERATED GALAXY EVOLUTION IN COMPACT GROUPS USING WHOLE-SKY WISE DATA
Walker, Lisa May
AffiliationUniv Arizona, Dept Astron
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationHIERARCHICAL FORMATION IN ACTION: CHARACTERIZING ACCELERATED GALAXY EVOLUTION IN COMPACT GROUPS USING WHOLE-SKY WISE DATA 2016, 821 (2):113 The Astrophysical Journal
JournalThe Astrophysical Journal
Rights© 2016. The American Astronomical Society. All rights reserved.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractCompact 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 [f(12)/f(4.6)]) versus (log [f(22)/f(3.4)]) 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.
VersionFinal published version
SponsorsNational Aeronautics and Space Administration; Alfred P. Sloan Foundation; U.S. Department of Energy Office of Science; Virginia Space Grant Consortium; University of Virginia College of Arts and Sciences; Natural Sciences and Engineering Research Council of Canada