Journal article
A DETAILED GRAVITATIONAL LENS MODEL BASED ON SUBMILLIMETER ARRAY AND KECK ADAPTIVE OPTICS IMAGING OF A HERSCHEL-ATLAS SUBMILLIMETER GALAXY AT z=4.243
The Astrophysical journal, Vol.756(2), 134
09/10/2012
DOI: 10.1088/0004-637X/756/2/134
Abstract
We present high-spatial resolution imaging obtained with the Submillimeter Array (SMA) at 880 μm and the Keck adaptive optics (AO) system at the KS-band of a gravitationally lensed submillimeter galaxy (SMG) at z = 4.243 discovered in the Herschel Astrophysical Terahertz Large Area Survey. The SMA data (angular resolution ≈0farcs6) resolve the dust emission into multiple lensed images, while the Keck AO KS-band data (angular resolution ≈0farcs1) resolve the lens into a pair of galaxies separated by 0farcs3. We present an optical spectrum of the foreground lens obtained with the Gemini-South telescope that provides a lens redshift of zlens = 0.595 ± 0.005. We develop and apply a new lens modeling technique in the visibility plane that shows that the SMG is magnified by a factor of μ = 4.1 ± 0.2 and has an intrinsic infrared (IR) luminosity of LIR = (2.1 ± 0.2) × 1013 L☉. We measure a half-light radius of the background source of rs = 4.4 ± 0.5 kpc which implies an IR luminosity surface density of ΣIR = (3.4 ± 0.9) × 1011 L☉ kpc−2, a value that is typical of z > 2 SMGs but significantly lower than IR luminous galaxies at z ∼ 0. The two lens galaxies are compact (rlens ≈ 0.9 kpc) early-types with Einstein radii of θE1 = 0.57 ± 0.01 and θE2 = 0.40 ± 0.01 that imply masses of Mlens1 = (7.4 ± 0.5) × 1010 M☉ and Mlens2 = (3.7 ± 0.3) × 1010 M☉. The two lensing galaxies are likely about to undergo a dissipationless merger, and the mass and size of the resultant system should be similar to other early-type galaxies at z ∼ 0.6. This work highlights the importance of high spatial resolution imaging in developing models of strongly lensed galaxies discovered by Herschel.
Details
- Title: Subtitle
- A DETAILED GRAVITATIONAL LENS MODEL BASED ON SUBMILLIMETER ARRAY AND KECK ADAPTIVE OPTICS IMAGING OF A HERSCHEL-ATLAS SUBMILLIMETER GALAXY AT z=4.243
- Creators
- R S Bussmann - Cornell UniversityM A Gurwell - Harvard UniversityHai Fu - University of Iowa, Physics and AstronomyDJB SmithS Dye - University of NottinghamR Auld - Cardiff UniversityM BaesA J BakerD Bonfield - University of HertfordshireA Cava - Universidad Complutense de MadridD L ClementsA Cooray - University of California, IrvineK Coppin - McGill UniversityH DannerbauerA Dariush - University of CambridgeG De Zotti - Scuola Internazionale Superiore di Studi AvanzatiL DunneS Eales - Cardiff UniversityJ FritzR Hopwood - Imperial College LondonE Ibar - UK Astronomy Technology CentreR J Ivison - UK Astronomy Technology CentreM J JarvisS Kim - University of Iowa, MathematicsL L Leeuw - University of South AfricaS Maddox - University of CanterburyM J MichallowskiM NegrelloE PascaleM Pohlen - Cardiff UniversityD A Riechers - Cornell UniversityE RigbyD ScottP Temi - Ames Research CenterP P Van der Werf - Leiden UniversityJ Wardlow - University of CopenhagenD Wilner - Harvard UniversityA Verma
- Resource Type
- Journal article
- Publication Details
- The Astrophysical journal, Vol.756(2), 134
- DOI
- 10.1088/0004-637X/756/2/134
- ISSN
- 0004-637X
- eISSN
- 1538-4357
- Publisher
- IOP PUBLISHING LTD
- Language
- English
- Date published
- 09/10/2012
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984199793602771
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