Logo
ScienceStack
Table of Contents
Fetching ...
Sign In

The Temperature of the Cosmic Microwave Background

D. J. Fixsen

TL;DR

The paper demonstrates how WMAP-derived velocity maps recalibrate FIRAS to yield an independent estimate of the CMB temperature, $T_{CMB} = 2.7260 ± 0.0013$ K, which is then reconciled with literature to obtain a precise consensus value. It uses a velocity-induced spectrum approach, leveraging the leading term proportional to $T ∂B/∂T$ to extract $T_{CMB}$, and combines FIRAS, WMAP, and historical data. The result supports a final, high-precision estimate of $T_{CMB} = 2.72548 ± 0.00057$ K, highlighting cross-calibration robustness across instruments and methods. The work reinforces the standard CMB temperature with cross-validated measurements across multiple platforms and calibration strategies, contributing to tight constraints on cosmic background radiation properties.

Abstract

The FIRAS data are independently recalibrated using the WMAP data to obtain a CMB temperature of 2.7260 +/- 0.0013. Measurements of the temperature of the cosmic microwave background are reviewed. The determination from the measurements from the literature is cosmic microwave background temperature of 2.72548 +/- 0.00057 K.

The Temperature of the Cosmic Microwave Background

TL;DR

The paper demonstrates how WMAP-derived velocity maps recalibrate FIRAS to yield an independent estimate of the CMB temperature, K, which is then reconciled with literature to obtain a precise consensus value. It uses a velocity-induced spectrum approach, leveraging the leading term proportional to to extract , and combines FIRAS, WMAP, and historical data. The result supports a final, high-precision estimate of K, highlighting cross-calibration robustness across instruments and methods. The work reinforces the standard CMB temperature with cross-validated measurements across multiple platforms and calibration strategies, contributing to tight constraints on cosmic background radiation properties.

Abstract

The FIRAS data are independently recalibrated using the WMAP data to obtain a CMB temperature of 2.7260 +/- 0.0013. Measurements of the temperature of the cosmic microwave background are reviewed. The determination from the measurements from the literature is cosmic microwave background temperature of 2.72548 +/- 0.00057 K.

Paper Structure

This paper contains 7 sections, 2 equations, 3 figures, 2 tables.

Table of Contents

  1. Introduction
  2. WMAP Velocity Map
  3. CMB Velocity Temperature
  4. FIRAS Uncertainty
  5. WMAP Uncertainty
  6. CMB Temperature
  7. SUMMARY AND CONCLUSIONS

Figures (3)

  • Figure 1: The templates used to fit the FIRAS data. The templates are in Galactic coordinates with the center of the Galaxy in the center of each Mollwide projection. The Galactic equator is a horizontal line across the middle of each figure. From top to bottom the templates are a)Data mask b)WMAP velocity c)C ii d)N ii e)Al26 f)H i g)Zodical model h)DIRBE band 8 i)DIRBE band 10 j)Haslam 408 MHz.
  • Figure 2: The crosses are the CMB temperature estimation for a given fraction of the brightest part of the sky excluded. The lines are the nominal +1 $\sigma$ and -1 $\sigma$ limits. The error bar is the adopted value and uncertainty inflated for the excess $\chi^2$.
  • Figure 3: The mean spectrum associated with the velocity of the solar system with respect to the CMB. The line is the a priori prediction based on the WMAP velocity and the previous FIRAS calibration. The uncertainties are the noise from the FIRAS measurements. The error bars are slightly misleading, because they do not show the correlations, but the correlated errors are properly treated in the fit.