Angular power spectrum of sterile neutrino decay lines: the role of eROSITA

14th International Conference on Topics in Astroparticle and Underground Physics

物理学;天文学

Zandanel, Fabio^1 ; Weniger, Christoph^1 ; Ando, Shin'Ichiro^1

GRAPPA Institute, University of Amsterdam, XH Amsterdam

1098, Netherlands^1

关键词: Active galactic nuclei;    Angular power spectrum;    Clusters of galaxies;    Cross correlations;    Decay life-time;    Sterile neutrinos;    Stringent constraints;    X-ray background;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/718/4/042067/pdf
DOI  :  10.1088/1742-6596/718/4/042067

学科分类：天文学(综合)

来源: IOP

【 摘 要 】

We study the potential of the angular auto and cross-correlation power spectrum of the cosmic X-ray background in identifying sterile neutrino dark matter taking as reference the performances of the soon-to-be-launched eROSITA satellite. The main astrophysical background sources in this case are active galactic nuclei, galaxies powered by X-ray binaries, and clusters of galaxies. We show that while sterile neutrino decays are always subdominant in the autocorrelation power spectra, they can be efficiently enhanced when cross-correlating with tracers of the dark matter distribution. We estimate that the four-years eROSITA all-sky survey will potentially provide very stringent constraints on the sterile neutrino decay lifetime by cross-correlating the cosmic X-ray background with the 2MASS galaxy catalogue. This will allow to firmly test the recently claimed 3.56-keV X-ray line found towards several clusters and galaxies and its decaying dark matter interpretation. We finally stress that the main limitation of this approach is due to the shot noise of the galaxy catalogues used as tracers for the dark matter distribution, a limitation that we need to overcome to fully exploit the potential of the eROSITA satellite in this context.