Spitzer Imaging of Strongly-Lensed Herschel-Selected Dusty Star Forming Galaxies
- Creators
- Ma, Brian
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Cooray, Asantha
Abstract
We present the rest-frame optical spectral energy distribution (SED) and stellar masses of six Herschel-selected gravitationally lensed dusty, star-forming galaxies (DSFGs) at 1 < z < 3. These galaxies were first identified with Herschel/SPIRE imaging data from the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS) and the Herschel Multi-tiered Extragalactic Survey (HerMES). The targets were observed with Spitzer/IRAC at 3.6 and 4.5 μm. Due to the spatial resolution of the IRAC observations at the level of 2'', the lensing features of a background DSFG in the near-infrared are blended with the flux from the foreground lensing galaxy in the IRAC imaging data. We make use of higher resolution Hubble/WFC3 or Keck/NIRC2 Adaptive Optics imaging data to fit light profiles of the foreground lensing galaxy (or galaxies) as a way to model the foreground components, in order to successfully disentangle the foreground lens and background source flux densities in the IRAC images. The flux density measurements at 3.6 and 4.5 μm, once combined with Hubble/WFC3 and Keck/NIRC2 data, provide important constraints on the rest-frame optical SED of the Herschel-selected lensed DSFGs. We model the combined UV- to millimeter-wavelength SEDs to establish the stellar mass, dust mass, star formation rate, visual extinction, and other parameters for each of these Herschel-selected DSFGs. These systems have inferred stellar masses in the range 8 × 10^(10)–4 × 10^(11) M_⊙ and star formation rates of around 100 M_⊙ yr^(−1). This puts these lensed submillimeter systems well above the SFR-M* relation observed for normal star-forming galaxies at similar redshifts. The high values of SFR inferred for these systems are consistent with a major merger-driven scenario for star formation.
Additional Information
© 2015 The American Astronomical Society. Received 2015 May 21; accepted 2015 October 5; published 2015 November 12. We thank the anonymous referee for the thoughtful feedback and insightful comments that have helped improve this paper. Financial support for this work was provided by NASA through the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Additional support for A. C., B. M., H. N., C. C., and N. T. was from the National Science Foundation with AST-1313319. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. We thank the native communities of Hawaii for their support of Keck and the Mauna Kea observatories. We recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from Mauna Kea. We encourage a meaningful dialogue between the astronomical and native Hawaiian communities on the future of Mauna Kea and the astronomical facilities there. The Herschel-ATLAS is a project with Herschel, which is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA. The H-ATLAS web site is http://www.h-atlas.org/. 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. The data presented in this paper will be released through the HerMES Database in Marseille, HeDaM (http://hedam.oamp.fr/HerMES/). The Dark Cosmology Centre is funded by the Danish National Research Foundation. I. O. acknowledges support from the European Research Council (ERC) in the form of Advanced Grant, cosmicism.Attached Files
Published - Ma_2015.pdf
Submitted - 1504.05254v3.pdf
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Additional details
- Eprint ID
- 63412
- Resolver ID
- CaltechAUTHORS:20160106-094420541
- Space Telescope Science Institute (STScI)
- NASA/JPL/Caltech
- AST-1313319
- NSF
- W. M. Keck Foundation
- Danish National Research Foundation
- COSMICISM
- European Research Council (ERC)
- Created
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2016-01-06Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)