Nayyeri, H. and Cooray, A. and Jullo, E. and Riechers, D. A. and Leung, T. K. D. and Frayer, D. T. and Gurwell, M. A. and Harris, A. I. and Ivison, R. J. and Negrello, M. and Oteo, I. and Amber, S. and Baker, A. J. and Calanog, J. and Casey, C. M. and Dannerbauer, H. and De Zotti, G. and Eales, S. and Fu, H. and Michałowski, M. J. and Timmons, N. and Wardlow, J. L. (2017) Herschel and Hubble Study of a Lensed Massive Dusty Starbursting Galaxy at z ˜ 3. The Astrophysical Journal, 844 (1): 82. ISSN 0004-637X
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Abstract
We present the results of combined deep Keck/NIRC2, HST/WFC3 near-infrared, and Herschel far-infrared observations of an extremely star-forming dusty lensed galaxy identified from the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS J133542.9+300401). The galaxy is gravitationally lensed by a massive WISE-identified galaxy cluster at z ˜ 1. The lensed galaxy is spectroscopically confirmed at z = 2.685 from detection of {CO} (1\to 0) by GBT and from detection of {CO} (3\to 2) obtained with CARMA. We use the combined spectroscopic and imaging observations to construct a detailed model of the background dusty lensed submillimeter galaxy (SMG), which allows us to study the source plane properties of the target. The best-fit lens model provides magnifications of μ star = 2.10 ± 0.11 and μ dust = 2.02 ± 0.06 for the stellar and dust components, respectively. Multiband data yield a magnification-corrected star formation rate of 1900(±200) M ⊙ yr-1 and a stellar mass of {6.8}-2.7+0.9× {10}11 {M}⊙ , consistent with a main sequence of star formation at z ˜ 2.6. The CO observations yield a molecular gas mass of 8.3(±1.0) × 1010 M ⊙, similar to the most massive star-forming galaxies, which together with the high star formation efficiency, are responsible for the intense observed star formation rates. The lensed SMG has a very short gas depletion timescale of ˜40 Myr. The high stellar mass and small gas fractions observed indicate that the lensed SMG likely has already formed most of its stellar mass and could be a progenitor of the most massive elliptical galaxies found in the local universe. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.