Maps of the Southern Millimeter-wave Sky from Combined 2500 deg$^2$ SPT-SZ and Planck Temperature Data

TL;DR

This paper combines data from the South Pole Telescope and Planck satellite to produce high-resolution maps of the southern millimeter-wave sky, effectively merging large-scale and small-scale information for improved analysis.

Contribution

It introduces a novel method for combining SPT-SZ and Planck data in spherical harmonic space, optimizing the use of each instrument's strengths for sky mapping.

Findings

Maps show excellent agreement with theoretical models.

Combined data improves large and small-scale sky coverage.

Results validate the data combination approach.

Abstract

We present three maps of the millimeter-wave sky created by combining data from the South Pole Telescope (SPT) and the Planck satellite. We use data from the SPT-SZ survey, a survey of 2540 deg$^2$ of the the sky with arcminute resolution in three bands centered at 95, 150, and 220 GHz, and the full-mission Planck temperature data in the 100, 143, and 217 GHz bands. A linear combination of the SPT-SZ and Planck data is computed in spherical harmonic space, with weights derived from the noise of both instruments. This weighting scheme results in Planck data providing most of the large-angular-scale information in the combined maps, with the smaller-scale information coming from SPT-SZ data. A number of tests have been done on the maps. We find their angular power spectra to agree very well with theoretically predicted spectra and previously published results.