Gravitational Lens Models Based on Submillimeter Array Imaging of Herschel-selected Strongly Lensed Sub-millimeter Galaxies at z > 1.5

Bussmann, R. S. and Pérez-Fournon, I. and Amber, S. and Calanog, J. and Gurwell, M. A. and Dannerbauer, H. and De Bernardis, F. and Fu, Hai and Harris, A. I. and Krips, M. and Lapi, A. and Maiolino, R. and Omont, A. and Riechers, D. and Wardlow, J. and Baker, A. J. and Birkinshaw, M. and Bock, J. and Bourne, N. and Clements, D. L. and Cooray, A. and De Zotti, G. and Dunne, L. and Dye, S. and Eales, S. and Farrah, D. and Gavazzi, R. and González Nuevo, J. and Hopwood, R. and Ibar, E. and Ivison, R. J. and Laporte, N. and Maddox, S. and Martínez-Navajas, P. and Michalowski, M. and Negrello, M. and Oliver, S. J. and Roseboom, I. G. and Scott, Douglas and Serjeant, S. and Smith, A. J. and Smith, Matthew and Streblyanska, A. and Valiante, E. and van der Werf, P. and Verma, A. and Vieira, J. D. and Wang, L. and Wilner, D. (2013) Gravitational Lens Models Based on Submillimeter Array Imaging of Herschel-selected Strongly Lensed Sub-millimeter Galaxies at z > 1.5. The Astrophysical Journal, 779 (1). p. 25. ISSN 0004-637X

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Abstract

Strong gravitational lenses are now being routinely discovered in wide-field surveys at (sub-)millimeter wavelengths. We present Submillimeter Array (SMA) high-spatial resolution imaging and Gemini-South and Multiple Mirror Telescope optical spectroscopy of strong lens candidates discovered in the two widest extragalactic surveys conducted by the Herschel Space Observatory: the Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS) and the Herschel Multi-tiered Extragalactic Survey (HerMES). From a sample of 30 Herschel sources with S 500 > 100 mJy, 21 are strongly lensed (i.e., multiply imaged), 4 are moderately lensed (i.e., singly imaged), and the remainder require additional data to determine their lensing status. We apply a visibility-plane lens modeling technique to the SMA data to recover information about the masses of the lenses as well as the intrinsic (i.e., unlensed) sizes (r half) and far-infrared luminosities (L FIR) of the lensed submillimeter galaxies (SMGs). The sample of lenses comprises primarily isolated massive galaxies, but includes some groups and clusters as well. Several of the lenses are located at z lens > 0.7, a redshift regime that is inaccessible to lens searches based on Sloan Digital Sky Survey spectroscopy. The lensed SMGs are amplified by factors that are significantly below statistical model predictions given the 500 μm flux densities of our sample. We speculate that this may reflect a deficiency in our understanding of the intrinsic sizes and luminosities of the brightest SMGs. The lensed SMGs span nearly one decade in L FIR (median L FIR = 7.9 × 1012 L ⊙) and two decades in FIR luminosity surface density (median ΣFIR = 6.0 × 1011 L ⊙ kpc-2). The strong lenses in this sample and others identified via (sub-)mm surveys will provide a wealth of information regarding the astrophysics of galaxy formation and evolution over a wide range in redshift. IMAGING OF HERSCHEL