HerMES: ALMA Imaging of Herschel-selected Dusty Star-forming Galaxies
- Creators
- Bussmann, R. S.
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Riechers, D.
- Fialkov, A.
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Scudder, J.
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Hayward, C. C.
- Cowley, W. I.
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Bock, J.
- Calanog, J.
- Chapman, S. C.
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Cooray, A.
- De Bernardis, F.
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Farrah, D.
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Fu, Hai
- Gavazzi, R.
- Hopwood, R.
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Ivison, R. J.
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Jarvis, M.
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Lacey, C.
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Loeb, A.
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Oliver, S. J.
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Pérez-Fournon, I.
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Rigopoulou, D.
- Roseboom, I. G.
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Scott, Douglas
- Smith, A. J.
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Vieira, J. D.
- Wang, L.
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Wardlow, J.
Abstract
The Herschel Multi-tiered Extragalactic Survey (HerMES) has identified large numbers of dusty star-forming galaxies (DSFGs) over a wide range in redshift. A detailed understanding of these DSFGs is hampered by the limited spatial resolution of Herschel. We present 870 μm 0."45 resolution imaging obtained with the Atacama Large Millimeter/submillimeter Array (ALMA) of a sample of 29 HerMES DSFGs that have far-infrared (FIR) flux densities that lie between the brightest of sources found by Herschel and fainter DSFGs found via ground-based surveys in the submillimeter region. The ALMA imaging reveals that these DSFGs comprise a total of 62 sources (down to the 5σ point-source sensitivity limit in our ALMA sample; σ ≈ 0.2 mJy). Optical or near-infrared imaging indicates that 36 of the ALMA sources experience a significant flux boost from gravitational lensing (µ > 1.1), but only six are strongly lensed and show multiple images. We introduce and make use of uvmcmcfit, a general-purpose and publicly available Markov chain Monte Carlo visibility-plane analysis tool to analyze the source properties. Combined with our previous work on brighter Herschel sources, the lens models presented here tentatively favor intrinsic number counts for DSFGs with a break near 8 mJy at 880 µm and a steep fall-off at higher flux densities. Nearly 70% of the Herschel sources break down into multiple ALMA counterparts, consistent with previous research indicating that the multiplicity rate is high in bright sources discovered in single-dish submillimeter or FIR surveys. The ALMA counterparts to our Herschel targets are located significantly closer to each other than ALMA counterparts to sources found in the LABOCA ECDFS Submillimeter Survey. Theoretical models underpredict the excess number of sources with small separations seen in our ALMA sample. The high multiplicity rate and small projected separations between sources seen in our sample argue in favor of interactions and mergers plausibly driving both the prodigious emission from the brightest DSFGs as well as the sharp downturn above S_(880) = 8 mJy.
Additional Information
© 2015 The American Astronomical Society. Received 2015 April 20; accepted 2015 July 14; published 2015 October 7. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. We thank the referee for useful comments that helped improve the clarity of the manuscript. This paper makes use of the following ALMA data: ADS/JAO.ALMA# 2011.0.00539.S. 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 the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO, and NAOJ. The results described in this paper are based on observations obtained with Herschel, an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. This research has made use of data from the HerMES project (http://hermes.sussex.ac.uk/). HerMES is a Herschel Key Programme utilizing Guaranteed Time from the SPIRE instrument team, ESAC scientists, and a mission scientist. HerMES is described in Oliver et al. (2012). The HerMES data presented in this paper will be released through the Herschel Database in Marseille (HeDaM). SPIRE has been developed by a consortium of institutes led by Cardiff Univ. (UK) and including: Univ. Lethbridge (Canada); NAOC (China); CEA, LAM (France); IFSI, Univ. Padua (Italy); IAC (Spain); Stockholm Observatory (Sweden); Imperial College London, RAL, UCL-MSSL, UKATC, Univ. Sussex (UK); and Caltech, JPL, NHSC, Univ. Colorado (USA). This development has been supported by national funding agencies: CSA (Canada); NAOC (China); CEA, CNES, CNRS (France); ASI (Italy); MCINN (Spain); SNSB (Sweden); STFC, UKSA (UK); and NASA (USA). The VIDEO imaging data are based on data products from observations made with ESO Telescopes at the La Silla or Paranal Observatories under ESO programme ID 179.A-2006. This paper is partly based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência, Tecnologia e Inovação (Brazil), and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina). The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. The Dark Cosmology Centre is funded by the Danish National Research Foundation. R. J. I. acknowledges support from European Research Council Advanced Investigator Grant, Cosmicism, 321302. C. C. H. is grateful to the Gordon and Betty Moore Foundation for financial support. Facilities: ALMA, Gemini-S.Attached Files
Published - Bussmann_2015p43.pdf
Submitted - 1504.05256v1.pdf
Erratum - Bussmann_2015_erratum.pdf
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Additional details
- Eprint ID
- 57068
- Resolver ID
- CaltechAUTHORS:20150428-152924348
- European Research Council (ERC)
- 321302
- Gordon and Betty Moore Foundation
- Created
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2015-04-28Created from EPrint's datestamp field
- Updated
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2023-06-01Created from EPrint's last_modified field
- Caltech groups
- TAPIR