SPT0346-52: NEGLIGIBLE AGN ACTIVITY IN A COMPACT, HYPER-STARBURST GALAXY AT z = 5.7

Journal Article · Thu Dec 01 04:00:00 EST 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/832/2/114· OSTI ID:22661011

Ma, Jingzhe; Gonzalez, Anthony H. ^[1]; Vieira, J. D.; Sreevani, J. ^[2]; Aravena, M. ^[3]; Ashby, M. L. N. ^[4]; Béthermin, M.; Breuck, C. de; Gullberg, B. ^[5]; Bothwell, M. S. ^[6]; Brandt, W. N. ^[7]; Carlstrom, J. E. ^[8]; Chapman, S. C. ^[9]; Hezaveh, Y. ^[10]; Litke, K.; Marrone, D. P.; Spilker, J. S. ^[11]; Malkan, M. ^[12]; McDonald, M. ^[13]; others, and

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1. Department of Astronomy, University of Florida, Gainesville, FL 32611 (United States)
2. Department of Astronomy and Department of Physics, University of Illinois, 1002 West Green St., Urbana, IL 61801 (United States)
3. Núcleo de Astronomía, Facultad de Ingeniería, Universidad Diego Portales, Av. Ejército 441, Santiago (Chile)
4. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
5. European Southern Observatory, Karl Schwarzschild Straße 2, D-85748 Garching (Germany)
6. Cavendish Laboratory, University of Cambridge, JJ Thompson Ave, Cambridge CB3 0HA (United Kingdom)
7. Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA 16802 (United States)
8. Kavli Institute for Cosmological Physics, University of Chicago, 5640 South Ellis Avenue, Chicago, IL 60637 (United States)
9. Dalhousie University, Halifax, Nova Scotia (Canada)
10. Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305 (United States)
11. Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)
12. Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States)
13. Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 37-582C, Cambridge, MA 02139 (United States)

We present Chandra ACIS-S and Australia Telescope Compact Array (ATCA) radio continuum observations of the strongly lensed dusty, star-forming galaxy SPT-S J034640-5204.9 (hereafter SPT0346-52) at z = 5.656. This galaxy has also been observed with ALMA, HST , Spitzer , Herschel , Atacama Pathfinder EXperiment, and the Very Large Telescope. Previous observations indicate that if the infrared (IR) emission is driven by star formation, then the inferred lensing-corrected star formation rate (SFR) (∼4500 M {sub ☉} yr{sup −1}) and SFR surface density Σ{sub SFR} (∼2000 M {sub ☉} yr{sup −1} kpc{sup −2}) are both exceptionally high. It remained unclear from the previous data, however, whether a central active galactic nucleus (AGN) contributes appreciably to the IR luminosity. The Chandra upper limit shows that SPT0346-52 is consistent with being star formation dominated in the X-ray, and any AGN contribution to the IR emission is negligible. The ATCA radio continuum upper limits are also consistent with the FIR-to-radio correlation for star-forming galaxies with no indication of an additional AGN contribution. The observed prodigious intrinsic IR luminosity of (3.6 ± 0.3) × 10{sup 13} L {sub ☉} originates almost solely from vigorous star formation activity. With an intrinsic source size of 0.61 ± 0.03 kpc, SPT0346-52 is confirmed to have one of the highest Σ{sub SFR} of any known galaxy. This high Σ{sub SFR}, which approaches the Eddington limit for a radiation pressure supported starburst, may be explained by a combination of very high star formation efficiency and gas fraction.

• OSTI ID: 22661011
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 832; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
AUSTRALIA
CORRELATIONS
GALACTIC EVOLUTION
GALAXIES
GALAXY NUCLEI
INFRARED RADIATION
LENSES
LUMINOSITY
RADIATION PRESSURE
RED SHIFT
STAR EVOLUTION
STARS
TELESCOPES
X RADIATION