A 2500 deg2 CMB Lensing Map from Combined South Pole Telescope and Planck Data

• Main Authors: Omori, Y, Chown, R, Simard, G, Story, KT, Aylor, K, Baxter, EJ, Benson, BA, Bleem, LE, Carlstrom, JE, Chang, CL, Cho, H-M, Crawford, TM, Crites, AT, de Haan, T, Dobbs, MA, Everett, WB, George, EM, Halverson, NW, Harrington, NL, Holder, GP, Hou, Z, Holzapfel, WL, Hrubes, JD, Knox, L, Lee, AT, Leitch, EM, Luong-Van, D, Manzotti, A, Marrone, DP, McMahon, JJ, Meyer, SS, Mocanu, LM, Mohr, JJ, Natoli, T, Padin, S, Pryke, C, Reichardt, CL, Ruhl, JE, Sayre, JT, Schaffer, KK, Shirokoff, E, Staniszewski, Z, Stark, AA, Vanderlinde, K, Vieira, JD, Williamson, R, Zahn, O
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: eScholarship, University of California 2017
• Subjects: Particle and High Energy Physics; Physical Sciences; cosmic background radiation; gravitational lensing: weak; large-scale structure of universe; Astronomical and Space Sciences; Atomic; Molecular; Nuclear; Particle and Plasma Physics; Physical Chemistry (incl. Structural); Astronomy & Astrophysics; Astronomical sciences; Space sciences; South Pole; South pole
• Online Access: https://escholarship.org/uc/item/08m9v5f6

We present a cosmic microwave background (CMB) lensing map produced from a linear combination of South Pole Telescope (SPT) and Planck temperature data. The 150 GHz temperature data from the 2500 deg2 SPT-SZ survey is combined with the Planck 143 GHz data in harmonic space to obtain a temperature map that has a broader ℓ coverage and less noise than either individual map. Using a quadratic estimator technique on this combined temperature map, we produce a map of the gravitational lensing potential projected along the line of sight. We measure the auto-spectrum of the lensing potential CLφφ, and compare it to the theoretical prediction for a ΛCDM cosmology consistent with the Planck 2015 data set, finding a best-fit amplitude of 0.95-0.06+0.06(stat.)0.01+0.01(sys.). The null hypothesis of no lensing is rejected at a significance of 24σ. One important use of such a lensing potential map is in cross-correlations with other dark matter tracers. We demonstrate this cross-correlation in practice by calculating the cross-spectrum, CLφG, between the SPT+Planck lensing map and Wide-field Infrared Survey Explorer (WISE) galaxies. We fit CLφG to a power law of the form PL = a(L/L0)-b with a, L 0, and b fixed, and find ηφG = CLφG/PL = 0.94-0.04+0.04, which is marginally lower, but in good agreement with ηφG = 1.00-0.01+0.02, the best-fit amplitude for the cross-correlation of Planck-2015 CMB lensing and WISE galaxies over ∼67% of the sky. The lensing potential map presented here will be used for cross-correlation studies with the Dark Energy Survey, whose footprint nearly completely covers the SPT 2500 deg2 field.