We present a multi-wavelength analysis of 48 submillimeter galaxies ( SMGs ) detected in the LABOCA/ACT Survey of Clusters at All Redshifts , LASCAR , which acquired new 870 \mu m and ATCA 2.1 GHz observations of ten galaxy clusters detected through their Sunyaev-Zel ’ dovich effect ( SZE ) signal by the Atacama Cosmology Telescope .
Far-infrared observations were also conducted with the PACS ( 100/160 \micron ) and SPIRE ( 250/350/500 \micron ) instruments on Herschel for sample subsets of five and six clusters .
LASCAR 870 \micron maps were reduced using a multi-scale iterative pipeline that removes the SZE increment signal , yielding point-source sensitivities of \sigma \sim 2 mJy beam ^ { -1 } .
We detect in total 49 sources at the 4 \sigma level , and conduct a detailed multi-wavelength analysis considering our new radio and far-IR observations plus existing near-IR and optical data .
One source is identified as a foreground galaxy , 28 SMGs are matched to single radio sources , 4 have double radio counterparts , and 16 are undetected at 2.1 GHz but tentatively associated in some cases to near-IR/optical sources .
We estimate photometric redshifts for 34 sources with secure ( 25 ) and tentative ( 9 ) matches at different wavelengths , obtaining a median z = 2.8 ^ { +2.1 } _ { -1.7 } .
Compared to previous results for single-dish surveys , our redshift distribution has a comparatively larger fraction of sources at z > 3 and the high-redshift tail is more extended .
This is consistent with millimeter spectroscopic confirmation of a growing number of high- z SMGs and relevant for testing of cosmological models .
Analytical lens modeling is applied to estimate magnification factors for 42 SMGs at cluster-centric radii > 1.2 \arcmin ; with the demagnified flux densities and source-plane areas , we obtain integral number counts that agree with previous submillimeter surveys .