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arXiv · 1707.09022

A dusty star-forming galaxy at z=6 revealed by strong gravitational lensing

Jorge A. Zavala·Alfredo Montaña·David H. Hughes·Min S. Yun·R. J. Ivison·Elisabetta Valiante·David Wilner·Justin Spilker·Itziar Aretxaga·Stephen Eales·Vladimir Avila-Reese·Miguel Chávez·Asantha Cooray·Helmut Dannerbauer·James S. Dunlop·Loretta Dunne·Arturo I. Gómez-Ruiz·Michal J. Michalowski·Gopal Narayanan·Hooshang Nayyeri·Ivan Oteo·Daniel Rosa González·David Sánchez-Argüelles·Stephen Serjeant·Matthew W. L. Smith·Elena Terlevich·Olga Vega·Alan Villalba·Paul van der Werf·Grant W. Wilson·Milagros Zeballos
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Abstract

Since their discovery, submillimetre-selected galaxies (SMGs) have revolutionized the field of galaxy formation and evolution. From the hundreds of square degrees mapped at submillimetre wavelengths, only a handful of sources have been confirmed to lie at z>5 and only two at z>6. All of these SMGs are rare examples of extreme starburst galaxies with star formation rates (SFRs) of >1000 M_sun/yr and therefore are not representative of the general population of dusty star-forming galaxies. Consequently, our understanding of the nature of these sources, at the earliest epochs, is still incomplete. Here we report the spectroscopic identification of a gravitationally amplified (mu = 9.3 +/- 1.0) dusty star-forming galaxy at z=6.027. After correcting for gravitational lensing, we derive an intrinsic less-extreme SFR of 380 +/- 50 M_sun/yr for this source and find that its gas and dust properties are similar to those measured for local Ultra Luminous Infrared Galaxies (ULIRGs), extending the local trends to a poorly explored territory in the early Universe. The star-formation efficiency of this galaxy is similar to those measured in its local analogues, despite a ~12 Gyr difference in cosmic time.

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Jorge A. Zavala, Alfredo Montaña, David H. Hughes, Min S. Yun, R. J. Ivison, Elisabetta Valiante, David Wilner, Justin Spilker, Itziar Aretxaga, Stephen Eales, Vladimir Avila-Reese, Miguel Chávez, Asantha Cooray, Helmut Dannerbauer, James S. Dunlop, Loretta Dunne, Arturo I. Gómez-Ruiz, Michal J. Michalowski, Gopal Narayanan, Hooshang Nayyeri, Ivan Oteo, Daniel Rosa González, David Sánchez-Argüelles, Stephen Serjeant, Matthew W. L. Smith, Elena Terlevich, Olga Vega, Alan Villalba, Paul van der Werf, Grant W. Wilson, Milagros Zeballos. 2017-07-27. A dusty star-forming galaxy at z=6 revealed by strong gravitational lensing. https://doi.org/10.1038/s41550-017-0297-8

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