A 2500 deg 2 CMB Lensing Map from Combined South Pole Telescope and Planck Data

• Published in: The Astrophysical Journal
• Main Authors: Omori, Y., Chown, R., Simard, G., Story, K. T., Aylor, K., Baxter, E. J., Benson, B. A., Bleem, L. E., Carlstrom, J. E., Chang, C. L., Cho, H-M., Crawford, T. M., Crites, A. T., Haan, T. de, Dobbs, M. A., Everett, W. B., George, E. M., Halverson, N. W., Harrington, N. L., Holder, G. P., Hou, Z., Holzapfel, W. L., Hrubes, J. D., Knox, L., Lee, A. T., Leitch, E. M., Luong-Van, D., Manzotti, A., Marrone, D. P., McMahon, J. J., Meyer, S. S., Mocanu, L. M., Mohr, J. J., Natoli, T., Padin, S., Pryke, C., Reichardt, C. L., Ruhl, J. E., Sayre, J. T., Schaffer, K. K., Shirokoff, E., Staniszewski, Z., Stark, A. A., Vanderlinde, K., Vieira, J. D., Williamson, R., Zahn, O.
• Language: unknown
• Published: 2022
• Subjects: South Pole; South pole
• Online Access: http://www.osti.gov/servlets/purl/1420120; https://www.osti.gov/biblio/1420120; https://doi.org/10.3847/1538-4357/aa8d1d

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 deg 2 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 C L φφ , 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, C L φG , between the SPT+Planck lensing map and Wide-field Infrared Survey Explorer (WISE) galaxies. We fit C L φG to a power law of the form P L = a(L/L 0 ) -b with a, L 0 , and b fixed, and find η φG = C L φG /P L = 0.94 -0.04 +0.04 , which is marginally lower, but in good agreement with η φG = 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 deg 2 field.