Testing the analytical blind separation method in simulated CMB polarization maps

¹ Center for Gravitation and Cosmology, College of Physical Science and Technology, Yangzhou University, Yangzhou 225009, PR China
e-mail: santoslarissa@hotmail.com
² School of Aeronautics and Astronautics, Shanghai Jiao Tong University, Shanghai 200240, PR China
³ Department of Astronomy, Shanghai Jiao Tong University, Shanghai 200240, PR China
⁴ School of Physics and Astronomy, Sun Yat-Sen University, 2 Daxue Road, Tangjia, Zhuhai 519082, PR China
⁵ CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China, Hefei 230026, PR China
⁶ School of Astronomy and Space Sciences, University of Science and Technology of China, Hefei 230026, PR China
⁷ IFSA Collaborative Innovation Center, Shanghai Jiao Tong University, Shanghai 200240, PR China
⁸ Tsung-Dao Lee Institute, Shanghai 200240, PR China
⁹ Divisão de Astrofísica, Instituto Nacional de Pesquisas Espaciais (INPE), 12227-010 São José dos Campos, SP, Brazil
¹⁰ Instituto de Física, Universidade de Brasília, 70919-970 Brasília, DF, Brazil
¹¹ Laboratoire Astroparticule et Cosmologie (APC), CNRS/IN2P3, Université Paris Diderot, 75205 Paris Cedex 13, France
¹² IRFU, CEA, Université Paris Saclay, 91191 Gif-sur-Yvette, France

Received: 21 August 2019
Accepted: 15 March 2021

Abstract

Context. Multi-frequency observations are needed to separate the cosmic microwave background (CMB) from foreground emission and accurately extract cosmological information from the data. The analytical blind separation (ABS) method is dedicated to extracting the CMB power spectrum from multi-frequency observations in the presence of contamination from astrophysical foreground emission and instrumental noise.

Aims. In this study, we apply the ABS method to simulated sky maps as could be observed with a future space-borne survey in order to test its capability of determining the CMB polarization E- and B-mode power spectra.

Methods. We present the ABS method performance on simulations for both a full-sky analysis and for an analysis concentrating on sky regions less impacted by Galactic foreground emission.

Results. We discuss the origin and minimization of biases in the estimated CMB polarization angular power spectra. We find that the ABS method performs quite well for the analysis of full-sky observations at intermediate and small angular scales, in spite of strong foreground contamination. On the largest scales, extra work is still required to reduce biases of various origins and the impact of confusion between CMB E and B polarization for partial sky analyses.