2017/01/31 by H. Nayyeri, A. Cooray, E. Jullo +19
Physics and Astronomy · #Astronomy and Astrophysical Research #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Galaxy merger #Gamma-ray bursts and supernovae #Interacting galaxy #Star formation #Stellar mass #astro-ph.GA
paper · pdf · doi:10.3847/1538-4357/aa7aa0
15 Pages, 10 Figures, 2 Tables. Accepted to the Astrophysical Journal
openalex created_date 2017/01/13 · arxiv created 2017/06/20 · openalex publication_date 2017/07/20 · arxiv updated 2017/08/02 · openalex updated_date 2026/08/06
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 by GBT and from detection of 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 , 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) × 10 10 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.