Bothwell, M. S.Aguirre, J. E.Chapman, S. C.Marrone, D. P.Vieira, J. D.Ashby, M. L. N.Aravena, M.Benson, B. A.Bock, J. J.Bradford, C. M.Brodwin, M.Carlstrom, J.Crawford, T. M.de Breuck, C.Downes, T. P.Fassnacht, C. D.Gonzalez, A. H.Greve, T. R.Gullberg, B.Hezaveh, Y.Holder, G. P.Holzapfel, W. L.Ibar, E.Ivison, R.Kamenetzky, J.Keisler, R.Lupu, R. E.Ma, J.Malkan, M.McIntyre, V.Murphy, E. J.Nguyen, H. T.Reichardt, C. L.Rosenman, M.Spilker, J. S.Stalder, B.Stark, A. A.Strandet, M.Vernet, J.Weiss, A.Welikala, N.2014-03-122014-03-122013-09-12Bothwell, M. S., J. E. Aguirre, S. C. Chapman, D. P. Marrone, et al. 2013. "SPT 0538-50: Physical conditions in the ISM of a strongly lensed dusty star-forming galaxy at z=2.8." Astrophysical Journal, 779 (1):670004-637Xhttp://hdl.handle.net/10222/45481http://dx.doi.org/10.1088/0004-637X/779/1/67We present observations of SPT-S J053816-5030.8, a gravitationally-lensed dusty star forming galaxy (DSFG) at z = 2.7817, first discovered at millimeter wavelengths by the South Pole Telescope. SPT 0538-50 is typical of the brightest sources found by wide-field millimeter-wavelength surveys, being lensed by an intervening galaxy at moderate redshift (in this instance, at z = 0.441). We present a wide array of multi-wavelength spectroscopic and photometric data on SPT 0538-50, including data from ALMA, Herschel PACS and SPIRE, Hubble, Spitzer, VLT, ATCA, APEX, and the SMA. We use high resolution imaging from HST to de-blend SPT 0538-50, separating DSFG emission from that of the foreground lens. Combined with a source model derived from ALMA imaging (which suggests a magnification factor of 21 +/- 4), we derive the intrinsic properties of SPT 0538-50, including the stellar mass, far-IR luminosity, star formation rate, molecular gas mass, and - using molecular line fluxes - the excitation conditions within the ISM. The derived physical properties argue that we are witnessing compact, merger-driven star formation in SPT 0538-50, similar to local starburst galaxies, and unlike that seen in some other DSFGs at this epoch.article779167