# Consistency of cosmic microwave background temperature measurements in three frequency bands in the 2500-square-degree SPT-SZ survey

## TL;DR

This paper tests the internal consistency of South Pole Telescope measurements of the CMB temperature anisotropy across three frequency bands, confirming their agreement within statistical uncertainties over a broad multipole range.

## Contribution

It introduces a comprehensive internal consistency test of multi-band CMB measurements from the SPT-SZ survey, validating the data's reliability for cosmological analysis.

## Key findings

- The six foreground-cleaned power spectra are consistent with the null hypothesis.
- The chi-squared fit yields a probability to exceed of 46%.
- Results support the internal consistency of multi-frequency CMB measurements.

## Abstract

We present an internal consistency test of South Pole Telescope (SPT) measurements of the cosmic microwave background (CMB) temperature anisotropy using three-band data from the SPT-SZ survey. These measurements are made from observations of ~2500 deg^2 of sky in three frequency bands centered at 95, 150, and 220 GHz. We combine the information from these three bands into six semi-independent estimates of the CMB power spectrum (three single-frequency power spectra and three cross-frequency spectra) over the multipole range 650 < l < 3000. We subtract an estimate of foreground power from each power spectrum and evaluate the consistency among the resulting CMB-only spectra. We determine that the six foreground-cleaned power spectra are consistent with the null hypothesis, in which the six cleaned spectra contain only CMB power and noise. A fit of the data to this model results in a chi-squared value of 236.3 for 235 degrees of freedom, and the probability to exceed this chi-squared value is 46%.