Dusty starburst galaxies in the early Universe as revealed by gravitational lensing
Abstract
In the past decade, our understanding of galaxy evolution has been revolutionized by the discovery that luminous, dusty starburst galaxies were 1,000 times more abundant in the early Universe than at present. It has, however, been difficult to measure the complete redshift distribution of these objects, especially at the highest redshifts (z > 4). Here we report a redshift survey at a wavelength of three millimetres, targeting carbon monoxide line emission from the star-forming molecular gas in the direction of extraordinarily bright millimetre-wave-selected sources. High-resolution imaging demonstrates that these sources are strongly gravitationally lensed by foreground galaxies. We detect spectral lines in 23 out of 26 sources and multiple lines in 12 of those 23 sources, from which we obtain robust, unambiguous redshifts. At least 10 of the sources are found to lie at z > 4, indicating that the fraction of dusty starburst galaxies at high redshifts is greater than previously thought. Models of lens geometries in the sample indicate that the background objects are ultra-luminous infrared galaxies, powered by extreme bursts of star formation.
Additional Information
© 2013 Macmillan Publishers Limited. Received 28 August 2012; accepted 12 February 2013. Published online 13 March 2013. The SPT is supported by the National Science Foundation, the Kavli Foundation and the Gordon and Betty Moore Foundation. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan), in cooperation with Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. The National Radio Astronomy Observatory is a facility of the NSF operated under cooperative agreement by Associated Universities, Inc. Partial support for this work was provided by NASA from the Space Telescope Science Institute. This work is based in part on observations made with Herschel, a European Space Agency Cornerstone Mission with significant participation by NASA. Work at McGill University is supported by NSERC, the CRC programme and CIfAR. Author Contributions: J.D.V. and D.P.M. wrote the text. S.C.C. took and reduced optical images and spectroscopy. A.W., C.D.B. and D.P.M. analysed the ALMA spectra. D.P.M., J.S.S. and Y.D.H. analysed the ALMA imaging data. J.D.V. reduced and analysed the Herschel data. Y.D.H. constructed the lens models. C.D.F. reduced optical images. All other authors (listed alphabetically) have contributed as part of the South Pole Telescope collaboration, by their involvement with the construction of the instrument, the initial discovery of the sources, multi-wavelength follow-up, and/or contributions to the text.Attached Files
Supplemental Material - nature12001-s1.pdf
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Additional details
- Eprint ID
- 37678
- Resolver ID
- CaltechAUTHORS:20130328-134810813
- NSF
- Kavli Foundation
- Gordon and Betty Moore Foundation
- NASA Space Telescope Science Institute (STSCI)
- Natural Sciences and Engineering Research Council of Canada (NSERC)
- CRC Programme
- Canadian Institute for Advanced Research (CIfAR)
- Created
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2013-04-10Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field