English

Cosmoglobe DR1 results. I. Improved Wilkinson Microwave Anisotropy Probe maps through Bayesian end-to-end analysis

Cosmology and Nongalactic Astrophysics 2023-11-29 v1

Abstract

We present Cosmoglobe Data Release 1, which implements the first joint analysis of WMAP and Planck LFI time-ordered data, processed within a single Bayesian end-to-end framework. This framework builds directly on a similar analysis of the LFI measurements by the BeyondPlanck collaboration, and approaches the CMB analysis challenge through Gibbs sampling of a global posterior distribution, simultaneously accounting for calibration, mapmaking, and component separation. The computational cost of producing one complete WMAP+LFI Gibbs sample is 812 CPU-hr, of which 603 CPU-hrs are spent on WMAP low-level processing; this demonstrates that end-to-end Bayesian analysis of the WMAP data is computationally feasible. We find that our WMAP posterior mean temperature sky maps and CMB temperature power spectrum are largely consistent with the official WMAP9 results. Perhaps the most notable difference is that our CMB dipole amplitude is 3366.2±1.4 μK3366.2 \pm 1.4\ \mathrm{\mu K}, which is 11 μK11\ \mathrm{\mu K} higher than the WMAP9 estimate and 2.5 σ2.5\ {\sigma} higher than BeyondPlanck; however, it is in perfect agreement with the HFI-dominated Planck PR4 result. In contrast, our WMAP polarization maps differ more notably from the WMAP9 results, and in general exhibit significantly lower large-scale residuals. We attribute this to a better constrained gain and transmission imbalance model. It is particularly noteworthy that the W-band polarization sky map, which was excluded from the official WMAP cosmological analysis, for the first time appears visually consistent with the V-band sky map. Similarly, the long standing discrepancy between the WMAP K-band and LFI 30 GHz maps is finally resolved, and the difference between the two maps appears consistent with instrumental noise at high Galactic latitudes. All maps and the associated code are made publicly available through the Cosmoglobe web page.

Keywords

Cite

@article{arxiv.2303.08095,
  title  = {Cosmoglobe DR1 results. I. Improved Wilkinson Microwave Anisotropy Probe maps through Bayesian end-to-end analysis},
  author = {D. J. Watts and A. Basyrov and J. R. Eskilt and M. Galloway and L. T. Hergt and D. Herman and H. T. Ihle and S. Paradiso and F. Rahman and H. Thommesen and R. Aurlien and M. Bersanelli and L. A. Bianchi and M. Brilenkov and L. P. L. Colombo and H. K. Eriksen and C. Franceschet and U. Fuskeland and E. Gjerløw and B. Hensley and G. A. Hoerning and K. Lee and J. G. S. Lunde and A. Marins and S. K. Nerval and S. K. Patel and M. Regnier and M. San and S. Sanyal and N. -O. Stutzer and A. Verma and I. K. Wehus and Y. Zhou},
  journal= {arXiv preprint arXiv:2303.08095},
  year   = {2023}
}

Comments

65 pages, 61 figures. Data available at cosmoglobe.uio.no. Submitted to A&A