A Caltech Library Service

The Infrared Properties of Submillimeter Galaxies: Clues from Ultradeep 70 μm Imaging

Huynh, Minh T. and Pope, Alexandra and Frayer, David T. and Scott, Douglas (2007) The Infrared Properties of Submillimeter Galaxies: Clues from Ultradeep 70 μm Imaging. Astrophysical Journal, 659 (1). pp. 305-313. ISSN 0004-637X. doi:10.1086/512096.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


We present 70 μm properties of submillimeter galaxies (SMGs) in the Great Observatories Origins Deep Survey (GOODS) North field. Out of 30 submillimeter galaxies (S850 > 2 mJy) in the central GOODS-N region, we find two with secure 70 μm detections. These are the first 70 μm detections of SMGs. One of the matched SMGs is at z~0.5, and has S70/S850 and S70/S24 ratios consistent with a cool galaxy. The second SMG(z=1.2) has infrared-submillimeter colors that indicate it is more actively forming stars. We examine the average 70 μm properties of the SMGs by performing a stacking analysis, which also allows us to estimate that S850 > 2 mJy SMGs contribute 9% ± 3% of the 70 μm background light. The S850/S70 colors of the SMG population as a whole is best fit by cool galaxies, and because of the redshifting effects these constraints are mainly on the lower z subsample. We fit spectral energy distributions (SEDs) to the far-infrared data points of the two detected SMGs and the average low-redshift SMG (zmedian = 1:4). We find that the average low-z SMG has a cooler dust temperature than local ultraluminous infrared galaxies (ULIRGs) of similar luminosity and an SED that is best fit by scaled-up versions of normal spiral galaxies. The average low-zSMGis found to have a typical dust temperature T = 21-33 K and infrared luminosity L8-1000 μm = 8:0 x 10^11 L☉. We estimate the AGN contribution to the total infrared luminosity of low-z SMGs is less than 23%.

Item Type:Article
Related URLs:
URLURL TypeDescription
Pope, Alexandra0000-0001-8592-2706
Frayer, David T.0000-0003-1924-1122
Scott, Douglas0000-0002-6878-9840
Additional Information:© 2007 The American Astronomical Society. Received 2006 October 11; accepted 2006 December 18. We thank the anonymous referee for helpful comments that improved this paper. M.T.H. would like to thank Anna Sajina for helpful discussions. A.P. and D.S. acknowledge support from the Natural Sciences and Engineering Research Council of Canada and the Canadian Space Agency. This work is based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech.
Funding AgencyGrant Number
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
Canadian Space AgencyUNSPECIFIED
Subject Keywords:galaxies: evolution — galaxies: formation — galaxies: starburst — submillimeter
Issue or Number:1
Record Number:CaltechAUTHORS:HUYapj07
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:11715
Deposited By: Archive Administrator
Deposited On:21 Sep 2008 05:38
Last Modified:08 Nov 2021 22:01

Repository Staff Only: item control page