STELLAR MASSES AND STAR FORMATION RATES OF LENSED, DUSTY, STAR-FORMING GALAXIES FROM THE SPT SURVEY

To understand cosmic mass assembly in the universe at early epochs, we primarily rely on measurements of the stellar masses and star formation rates (SFRs) of distant galaxies. In this paper, we present stellar masses and SFRs of six high-redshift (2.8 ≤ z ≤ 5.7) dusty, star-forming galaxies (DSFGs)...

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Bibliographic Details
Published in:The Astrophysical Journal
Main Authors: Ma, Jingzhe, Gonzalez, Anthony H, Spilker, JS, Strandet, M, Ashby, MLN, Aravena, M, Béthermin, M, Bothwell, MS, de Breuck, C, Brodwin, M, Chapman, SC, Fassnacht, CD, Greve, TR, Gullberg, B, Hezaveh, Y, Malkan, M, Marrone, DP, Saliwanchik, BR, Vieira, JD, Weiss, A, Welikala, N
Format: Article in Journal/Newspaper
Language:unknown
Published: eScholarship, University of California 2015
Subjects:
galaxies: high-redshift
astro-ph.GA
Astronomical and Space Sciences
Atomic
Molecular
Nuclear
Particle and Plasma Physics
Physical Chemistry (incl. Structural)
Astronomy & Astrophysics
South pole
Online Access:https://escholarship.org/uc/item/21n4d5h5
https://escholarship.org/content/qt21n4d5h5/qt21n4d5h5.pdf
https://doi.org/10.1088/0004-637x/812/1/88
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Summary:To understand cosmic mass assembly in the universe at early epochs, we primarily rely on measurements of the stellar masses and star formation rates (SFRs) of distant galaxies. In this paper, we present stellar masses and SFRs of six high-redshift (2.8 ≤ z ≤ 5.7) dusty, star-forming galaxies (DSFGs) that are strongly gravitationally lensed by foreground galaxies. These sources were first discovered by the South Pole Telescope (SPT) at millimeter wavelengths and all have spectroscopic redshifts and robust lens models derived from Atacama Large Millimeter/submillimeter Array observations. We have conducted follow-up observations to obtain multi-wavelength imaging data using the Hubble Space Telescope (HST), Spitzer, Herschel, and the Atacama Pathfinder EXperiment. We use the high-resolution HST/Wide Field Camera 3 images to disentangle the background source from the foreground lens in Spitzer/IRAC data. The detections and upper limits provide important constraints on the spectral energy distributions (SEDs) for these DSFGs, yielding stellar masses, IR luminosities, and SFRs. The SED fits of six SPT sources show that the intrinsic stellar masses span a range more than one order of magnitude with a median value ∼5 ×1010 Mo. The intrinsic IR luminosities range from 4 × 1012 Lo to 4 × 1013 Lo. They all have prodigious intrinsic SFRs of 510-4800 Mo yr-1. Compared to the star-forming main sequence (MS), these six DSFGs have specific SFRs that all lie above the MS, including two galaxies that are a factor of 10 higher than the MS. Our results suggest that we are witnessing ongoing strong starburst events that may be driven by major mergers.

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