The ultraviolet and infrared star formation rates of compact group galaxies: an expanded sample
Gallagher, Sarah C.
Desjardins, Tyler D.
Walker, Lisa May
Johnson, Kelsey E.
Hornschemeier, Ann E.
Durrell, Pat R.
AffiliationUniv Arizona, Steward Observ
MetadataShow full item record
PublisherOXFORD UNIV PRESS
CitationThe ultraviolet and infrared star formation rates of compact group galaxies: an expanded sample 2016, 459 (3):2948 Monthly Notices of the Royal Astronomical Society
Rights© 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society
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AbstractCompact groups of galaxies provide insight into the role of low-mass, dense environments in galaxy evolution because the low velocity dispersions and close proximity of galaxy members result in frequent interactions that take place over extended time-scales. We expand the census of star formation in compact group galaxies by Tzanavaris et al. (2010) and collaborators with Swift UVOT, Spitzer IRAC and MIPS 24 mu m photometry of a sample of 183 galaxies in 46 compact groups. After correcting luminosities for the contribution from old stellar populations, we estimate the dust-unobscured star formation rate (SFRUV) using the UVOT uvw2 photometry. Similarly, we use the MIPS 24 mu m photometry to estimate the component of the SFR that is obscured by dust (SFRIR). We find that galaxies which are MIR-active (MIR-'red'), also have bluer UV colours, higher specific SFRs, and tend to lie in H I-rich groups, while galaxies that are MIR-inactive (MIR-'blue') have redder UV colours, lower specific SFRs, and tend to lie in H I-poor groups. We find the SFRs to be continuously distributed with a peak at about 1 M-circle dot yr(-1), indicating this might be the most common value in compact groups. In contrast, the specific SFR distribution is bimodal, and there is a clear distinction between star-forming and quiescent galaxies. Overall, our results suggest that the specific SFR is the best tracer of gas depletion and galaxy evolution in compact groups.
VersionFinal published version
SponsorsNatural Science and Engineering Research Council; Ontario Early Researcher Award Program