DYNAMICAL STRUCTURE OF THE MOLECULAR INTERSTELLAR MEDIUM IN AN EXTREMELY BRIGHT, MULTIPLY LENSED z {approx_equal} 3 SUBMILLIMETER GALAXY DISCOVERED WITH HERSCHEL

Journal Article · Fri May 20 00:00:00 EDT 2011 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/733/1/L12· OSTI ID:21562666

Riechers, Dominik A; Cooray, A; Carpenter, J M; Bock, J ^[1]; Omont, A ^[2]; Neri, R; Cox, P ^[3]; Harris, A I ^[4]; Baker, A J ^[5]; Frayer, D T ^[6]; Auld, R ^[7]; Aussel, H; Chanial, P ^[8]; Beelen, A ^[9]; Blundell, R ^[10]; Brisbin, D ^[11]; Burgarella, D ^[12]; Chapman, S C ^[13]

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1. Astronomy Department, California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States)
2. Institut d'Astrophysique de Paris, CNRS and Universite Pierre et Marie Curie, 98bis Bd Arago, F-75014 Paris (France)
3. Institut de RadioAstronomie Millimetrique, 300 Rue de la Piscine, Domaine Universitaire, F-38406 Saint Martin d'Heres (France)
4. Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States)
5. Department of Physics and Astronomy, Rutgers, the State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854-8019 (United States)
6. National Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV 24944 (United States)
7. School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff CF24 3AA (United Kingdom)
8. Laboratoire AIM-Paris-Saclay, CEA/DSM/Irfu-CNRS-Universite Paris Diderot, CE-Saclay, pt courrier 131, F-91191 Gif-sur-Yvette (France)
9. Institut d'Astrophysique Spatiale, Universite Paris-Sud XI, bat 121, F-91405 Orsay Cedex (France)
10. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)
11. Space Science Building, Cornell University, Ithaca, NY, 14853-6801 (United States)
12. Laboratoire d'Astrophysique de Marseille, OAMP, Universite Aix-marseille, CNRS, 38 rue Frederic Joliot-Curie, F-13388 Marseille Cedex 13 (France)
13. Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom)

We report the detection of CO(J = 5 {yields} 4), CO(J = 3 {yields} 2), and CO(J = 1 {yields} 0) emission in the strongly lensed, Herschel/SPIRE-selected submillimeter galaxy (SMG) HERMES J105751.1+573027 at z = 2.9574 {+-} 0.0001, using the Plateau de Bure Interferometer, the Combined Array for Research in Millimeter-wave Astronomy, and the Green Bank Telescope. The observations spatially resolve the molecular gas into four lensed images with a maximum separation of {approx}9'' and reveal the internal gas dynamics in this system. We derive lensing-corrected CO line luminosities of L'{sub CO(1-0)} = (4.17 {+-} 0.41), L'{sub CO(3-2)} = (3.96 {+-} 0.20), and L'{sub CO(5-4)} = (3.45 {+-} 0.20) x 10{sup 10} ({mu}{sub L}/10.9){sup -1} K km s{sup -1} pc{sup 2}, corresponding to luminosity ratios of r{sub 31} = 0.95 {+-} 0.10, r{sub 53} = 0.87 {+-} 0.06, and r{sub 51} = 0.83 {+-} 0.09. This suggests a total molecular gas mass of M{sub gas} = 3.3x10{sup 10} ({alpha}{sub CO}/0.8) ({mu}{sub L}/10.9){sup -1} M{sub sun}. The gas mass, gas mass fraction, gas depletion timescale, star formation efficiency, and specific star formation rate are typical for an SMG. The velocity structure of the gas reservoir suggests that the brightest two lensed images are dynamically resolved projections of the same dust-obscured region in the galaxy that are kinematically offset from the unresolved fainter images. The resolved kinematics appear consistent with the complex velocity structure observed in major, 'wet' (i.e., gas-rich) mergers. Major mergers are commonly observed in SMGs and are likely to be responsible for fueling their intense starbursts at high gas consumption rates. This study demonstrates the level of detail to which galaxies in the early universe can be studied by utilizing the increase in effective spatial resolution and sensitivity provided by gravitational lensing.

• OSTI ID: 21562666
• Journal Information: Astrophysical Journal Letters, Vol. 733, Issue 1; Other Information: DOI: 10.1088/2041-8205/733/1/L12; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
CARBON MONOXIDE
COSMOLOGY
GALACTIC EVOLUTION
GALAXIES
INTERFEROMETERS
INTERSTELLAR SPACE
LUMINOSITY
MASS
STAR EVOLUTION
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
EVOLUTION
MEASURING INSTRUMENTS
OPTICAL PROPERTIES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SPACE