MIPS J142824.0+352619: A hyperluminous starburst galaxy at z=1.325

Using the SHARC-II camera at the Caltech Submillimeter Observatory to obtain 350 mu m images of sources detected with the MIPS instrument on Spitzer, we have discovered a remarkable object at z =1.325 +/- 0.002 with an apparent far-infrared luminosity of 3.2( +/- 0.7) x 10(13) L-circle dot. Unlike other z > 1 sources of comparable luminosity selected from mid-IR surveys, MIPS J142824.0 + 352619 lacks any trace of AGN activity, and is likely a luminous analog of galaxies selected locally by IRAS, or at high redshift in the submillimeter. This source appears to be lensed by a foreground elliptical galaxy at z = 1.034, although the amplification is likely modest ( less than or similar to 10). We argue that the contribution to the observed optical/near-IR emission from the foreground galaxy is small, and hence are able to present the rest-frame UV through radio spectral energy distribution of this galaxy. Due to its unusually high luminosity, MIPS J142824.0 + 352619 presents a unique chance to study a high-redshift dusty starburst galaxy in great detail.