Spitzer imaging of Herschel-atlas gravitationally lensed submillimeter sources
da Cunha, E.
de Zotti, G.
van der Werf, P.
We present physical properties of two submillimeter selected gravitationally lensed sources, identified in the Herschel Astrophysical Terahertz Large Area Survey. These submillimeter galaxies (SMGs) have flux densities >100 mJy at 500 mu m, but are not visible in existing optical imaging. We fit light profiles to each component of the lensing systems in Spitzer IRAC 3.6 and 4.5 mu m data and successfully disentangle the foreground lens from the background source in each case, providing important constraints on the spectral energy distributions (SEDs) of the background SMG at rest-frame optical-near-infrared wavelengths. The SED fits show that these two SMGs have high dust obscuration with A(V) similar to 4-5 and star formation rates of similar to 100M(circle dot) yr(-1). They have low gas fractions and low dynamical masses compared with 850 mu m selected galaxies.