Infrared Luminosities and Dust Properties of z ~ 2 Dust-Obscured Galaxies - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




Infrared Luminosities and Dust Properties of z ~ 2 Dust-Obscured Galaxies - Astrophysics > Cosmology and Nongalactic Astrophysics - Download this document for free, or read online. Document in PDF available to download.

Abstract: We present SHARC-II 350um imaging of twelve 24um-bright F 24um > 0.8 mJyDust-Obscured Galaxies DOGs and CARMA 1mm imaging of a subset of 2 DOGs, allselected from the Bootes field of the NOAO Deep Wide-Field Survey. Detectionsof 4 DOGs at 350um imply IR luminosities which are consistent within a factorof 2 of expectations based on a warm dust spectral energy distribution SEDscaled to the observed 24um flux density. The 350um upper limits for the 8non-detected DOGs are consistent with both Mrk231 and M82 warm dust SEDs, butexclude cold dust Arp220 SEDs. The two DOGs targeted at 1mm were not detectedin our CARMA observations, placing strong constraints on the dust temperature:T dust > 35-60 K. Assuming these dust properties apply to the entire sample, wefind dust masses of ~3x10^8 M sun. In comparison to other dusty z ~ 2 galaxypopulations such as sub-millimeter galaxies SMGs and other Spitzer-selectedhigh-redshift sources, this sample of DOGs has higher IR luminosities 2x10^13L sun vs. 6x10^12 L sun for the other galaxy populations, warmer dusttemperatures >35-60 K vs. ~30 K, and lower inferred dust masses 3x10^8 M sunvs. 3x10^9 M sun. Herschel and SCUBA-2 surveys should be able to detecthundreds of these power-law dominated DOGs. We use HST and Spitzer-IRAC data toestimate stellar masses of these sources and find that the stellar to gas massratio may be higher in our 24um-bright sample of DOGs than in SMGs and otherSpitzer-selected sources. Although larger sample sizes are needed to provide adefinitive conclusion, the data are consistent with an evolutionary trend inwhich the formation of massive galaxies at z~2 involves a sub-millimeterbright, cold-dust and star-formation dominated phase followed by a 24um-bright,warm-dust and AGN-dominated phase.



Author: R. S. Bussmann, Arjun Dey, C. Borys, V. Desai, B. T. Jannuzi, E. Le Floc'h, J. Melbourne, K. Sheth, B. T. Soifer

Source: https://arxiv.org/







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