DISCOVERY OF A MULTIPLY LENSED SUBMILLIMETER GALAXY IN EARLY HerMES HERSCHEL/SPIRE* DATA

Journal article

We report the discovery of a bright (f (250 μm)>400 mJy), multiply lensed submillimeter galaxy HERMES J105751.1+573027 in Herschel/SPIRE Science Demonstration Phase data from the HerMES project. Interferometric 880 μm Submillimeter Array observations resolve at least four images with a large separation of ∼9″. A high-resolution adaptive optics Kp image with Keck/NIRC2 clearly shows strong lensing arcs. Follow-up spectroscopy gives a redshift of z = 2.9575, and the lensing model gives a total magnification of μ ∼ 11 ± 1. The large image separation allows us to study the multi-wavelength spectral energy distribution (SED) of the lensed source unobscured by the central lensing mass. The far-IR/millimeter-wave SED is well described by a modified blackbody fit with an unusually warm dust temperature, 88 ± 3 K. We derive a lensing-corrected total IR luminosity of (1.43 ± 0.09) × 1013 L⊙, implying a star formation rate of ∼2500 M⊙ yr-1. However, models primarily developed from brighter galaxies selected at longer wavelengths are a poor fit to the full optical-to-millimeter SED. A number of other strongly lensed systems have already been discovered in early Herschel data, and many more are expected as additional data are collected. © 2011. The American Astronomical Society. All rights reserved.

Authors: Conley, A; Cooray, A; Vieira, J; Solares, E; Kim, S

• Publication status: Published
• Journal: ASTROPHYSICAL JOURNAL LETTERS
• Volume: 732
• Issue: 2
• Pages: L35-L35
• Publication date: 2011-05-10
• DOI: 10.1088/2041-8205/732/2/L35
• EISSN: 2041-8213
• ISSN: 2041-8205
• Language: English
• Keywords: galaxies: starburst; galaxies: high-redshift; gravitational lensing: strong; submillimeter: galaxies