| Summary: | We perform a combined fit to angular power spectra of unresolved infrared (IR) point sources from the Planck satellite (at 217, 353, 545, and 857 GHz, over angular scales 100 ≾ ℓ ≾ 2200), the Balloon-borne Large-Aperture Submillimeter Telescope (BLAST; 250, 350, and 500μm; 1000 ≾ ℓ ≾ 9000), and from correlating BLAST and Atacama Cosmology Telescope (ACT; 148 and 218 GHz) maps. We find that the clustered power over the range of angular scales and frequencies considered is well fitted by a simple power law of the form C^(clust)_ℓ ∠ℓ^(-n) with n = 1.25 ± 0.06. While the IR sources are understood to lie at a range of redshifts, with a variety of dust properties, we find that the frequency dependence of the clustering power can be described by the square of a modified blackbody, ν^(β)B(ν, T_(eff)), with a single emissivity index β = 2.20 ± 0.07 and effective temperature T_(eff) = 9.7 K. Our predictions for the clustering amplitude are consistent with existing ACT and South Pole Telescope results at around 150 and 220 GHz, as is our prediction for the effective dust spectral index, which we find to be α_(150–220) = 3.68±0.07 between 150 and 220 GHz. Our constraints on the clustering shape and frequency dependence can be used to model the IR clustering as a contaminant in cosmic microwave background anisotropy measurements. The combined Planck and BLAST data also rule out a linear bias clustering model. © 2012 The American Astronomical Society. Received 2011 August 23; accepted 2012 April 13; published 2012 June 4. This work was supported by the U.S. National Science Foundation through awards AST-0408698 for the ACT project, and PHY-0355328, AST-0707731, and PIRE-0507768. G.A. is supported by an STFC studentship and funding was also provided by Princeton University and the University of Pennsylvania, RCUK Fellowship (J.D.), ERC grant 259505 (J.D.), and NASA grant NNX08AH30G (A.H.). ACT. operates in the Chajnantor Science Preserve in Northern Chile under the auspices of the Comisión ...
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