Observational evidences for the existence of 17.4 keV decaying degenerate sterile neutrinos near the Galactic Center

TL;DR

This paper presents observational evidence supporting the existence of 17.4 keV sterile neutrinos near the Galactic Center, explaining X-ray emissions and hot gas heating, and discusses their potential detectability in future experiments.

Contribution

It provides observational evidence for 17.4 keV sterile neutrinos near the Galactic Center and links their decay properties to astrophysical phenomena and future neutrino oscillation experiments.

Findings

Sterile neutrinos can account for 8.7 keV X-ray excess.

Decay rate and mixing angle are consistent with inflation models.

Sterile neutrino oscillations might be detectable soon.

Abstract

We show that the existence of a degenerate halo of sterile neutrinos with rest mass of 17.4 keV near the Galactic Center can account for both the excess 8.7 keV emission observed by the $Suzaku$ mission and the power needed ($10^{40}$ erg s$^{-1}$) to maintain the high temperature of the hot gas (8 keV) near the Galactic Center. The required decay rate and mixing angle of the sterile neutrinos are $\Gamma \ge 5 \times 10^{-20}$ s$^{-1}$ and $\sin^22 \theta \sim 10^{-3}-10^{-4}$ respectively. These values are consistent with a low reheating temperature in the inflation model, and suggest the exciting possibility that the sterile - active neutrino oscillation can be visible in near future experiments.