Multi-wavelength Lens Reconstruction of a Planck and Herschel-detected Star-bursting Galaxy
Baes, Maarten; Fu, Hai; Clements, David L.; Gladders, Michael D.; Eales, Stephen A.; Cooray, Asantha; Nayyeri, Hooshang; Scott, Douglas; Jullo, Eric; Michałowski, Michał J.; da Cunha, Elisabete; Greenslade, Joshua; Dye, Simon; Riechers, Dominik A.; Valiante, Elisabetta; Messias, Hugo; Gonzalez-Nuevo, Joaquin; Bussmann, R. Shane; Pérez-Fournon, Ismael; Furlanetto, Cristina; Oteo, Iván; Gurwell, Mark; Timmons, Nicholas; Calanog, Jae
United States, France, Belgium, United Kingdom, Australia, Brazil, Spain, Portugal, Germany, Canada
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× {10}11 {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.