Discovery of a lensed ultrabright submillimeter galaxy at z = 2.0439. Póster

Abstract

We report an ultra-bright lensed submillimeter galaxy (SMG) at z = 2.0439, WISE J132934.18+224327.3, identified as a result of a full-sky cross-correlation of the AllWISE and Planck compact source catalogs aimed to search for bright analogs of the submillimeter galaxy SMMJ2135, the Cosmic Eyelash. Inspection of archival SCUBA-2 observations of the candidates revealed a source with fluxes (S850μm= 130 mJy) consistent with the Planck measurements. The centroid of the SCUBA-2 source coincides within 1 arcsec with the position of the AllWISE mid-IR source, and, remarkably, with an arc shaped lensed galaxy in HST images at visible wavelengths. Low-resolution rest-frame UV-optical spectroscopy of this lensed galaxy obtained with 10.4 m GTC reveals the typical absorption lines of a starburst galaxy. Gemini-N near-IR spectroscopy provided a clear detection of H_ emission. The lensed source appears to be gravitationally magnified by a massive foreground galaxy cluster lens at z = 0.44, modeling with Lenstool indicates a lensing amplification factor of 11±2. We determine an intrinsic rest-frame 8-1000-μm luminosity, LIR, of (1.3±0.1)×1013 L⊙, and a likely star-formation rate (SFR) of _ 500−2000 M⊙yr−1 . The SED shows a remarkable similarity with the Cosmic Eyelash from optical-mid/IR to sub-millimeter/radio, albeit at higher fluxes.