Hainline, L.J. and Blain, A.W. and Smail, I. and Frayer, D.T. and Chapman, S.C. and Ivison, R.J. and Alexander, D.M. (2009) 'A mid-infrared imaging survey of submillimeter-selected galaxies with the Spitzer space telescope.', Astrophysical journal., 699 (2). pp. 1610-1632.
We present Spitzer-IRAC and MIPS mid-IR observations of a sample of 73 radio-detected submillimeter-selected galaxies (SMGs) with spectroscopic redshifts, the largest such sample published to date. From our data, we find that IRAC colors of SMGs are much more uniform as compared with rest-frame UV and optical colors, and z>1.5 SMGs tend to be redder in their mid-IR colors than both field galaxies and lower-z SMGs. However, the IRAC colors of the SMGs overlap those of field galaxies sufficiently that color-magnitude and color-color selection criteria suggested in the literature to identify SMG counterparts produce ambiguous counterparts within an 8'' radius in 20%-35% of cases. We use a rest-frame J-H versus H-K color-color diagram and a S 24/S 8.0 versus S 8.0/S 4.5 color-color diagram to determine that 13%-19% of our sample are likely to contain active galactic nuclei which dominate their mid-IR emission. We observe in the rest-frame JHK colors of our sample that the rest-frame near-IR emission of SMGs does not resemble that of the compact nuclear starburst observed in local ultraluminous IR galaxies and is consistent with more widely distributed star formation. We take advantage of the fact that many high-z galaxy populations selected at different wavelengths are detected by Spitzer to carry out a brief comparison of mid-IR properties of SMGs to UV-selected high-z galaxies, 24 μm-selected galaxies, and high-z radio galaxies, and find that SMGs have mid-IR fluxes and colors which are consistent with being more massive and more reddened than UV-selected galaxies, while the IRAC colors of SMGs are most similar to powerful high-z radio galaxies.
|Keywords:||Galaxies, Evolution, Formation, High-redshift, Infrared.|
|Full text:||(VoR) Version of Record|
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|Publisher Web site:||http://dx.doi.org/10.1088/0004-637X/699/2/1610|
|Publisher statement:||© 2009. The American Astronomical Society. All rights reserved. Printed in the U.S.A.|
|Date accepted:||No date available|
|Date deposited:||05 September 2013|
|Date of first online publication:||July 2009|
|Date first made open access:||No date available|
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