N. Timmons, A. Cooray, D. A. Riechers, H. Nayyeri, H. Fu, E. Jullo, M. D. Gladders, M. Baes, R. S. Bussmann, Jae Calanog, D. L. Clements, E. da Cunha, S. Dye, S. Eales, C. Furlanetto, J. González-Nuevo, J. Greenslade, M. Gurwell, H. Messias, M. J. Michałowski, I. Oteo, I. Pérez-Fournon, D. Scott, E. Valiante
Abstract
We present a source-plane reconstruction of a Herschel and Planck-detected gravitationally lensed dusty star-forming galaxy (DSFG) at z = 1.68 using Hubble, Submillimeter Array (SMA), and Keck observations. The background submillimeter galaxy (SMG) is strongly lensed by a foreground galaxy cluster at z = 0.997 and appears as an arc with a length of ~15″ in the optical images. The continuum dust emission, as seen by SMA, is limited to a single knot within this arc. We present a lens model with source-plane reconstructions at several wavelengths to show the difference in magnification between the stars and dust, and highlight the importance of multi-wavelength lens models for studies involving lensed DSFGs. We estimate the physical properties of the galaxy by fitting the flux densities to model spectral energy distributions leading to a magnification-corrected star-formation rate (SFR) of 390 ± 60 M☉ yr-1 and a stellar mass of 1.1 ± 0.4×1011 M☉ . These values are consistent with high-redshift massive galaxies that have formed most of their stars already. The estimated gas-to-baryon fraction, molecular gas surface density, and SFR surface density have values of 0.43 ± 0.13, 350 ± 200 M☉ pc-2, and ~12 ± 7 M☉ yr-1 kpc-2, respectively. The ratio of SFR surface density to molecular gas surface density puts this among the most star-forming systems, similar to other measured SMGs and local ULIRGs.
Keywords
cosmology: observations, galaxies: evolution, infrared: galaxies, submillimeter: galaxies
The Astrophysical Journal
Volume 829, Number 1
2016 September
