New constraints on sterile neutrino dark matter from the Galactic Center

TL;DR

This paper derives new, stringent constraints on sterile neutrino dark matter parameters from X-ray observations of the Galactic center, highlighting the impact of different density profiles and the RAR fermionic model on the allowed mass window.

Contribution

It introduces a novel analysis using the RAR fermionic dark matter profile, narrowing the sterile neutrino mass window to 10-15 keV within the $ u$MSM model.

Findings

Allowed sterile neutrino mass window is 10-15 keV with RAR profile.

X-ray flux observations impose stringent constraints on sterile neutrino parameters.

The dark matter density profile significantly affects the parameter bounds.

Abstract

We calculate the most stringent constraints up to date on the parameter space for sterile neutrino warm dark matter models possessing a radiative decay channel into X-rays. These constraints arise from the X-ray flux observations from the Galactic center (central parsec), taken by the XMM and NuSTAR missions. We compare the results obtained from using different dark matter density profiles for the Milky Way, such as NFW, Burkert or Einasto, to that produced by the Ruffini-Arg\"uelles-Rueda (RAR) fermionic model, which has the distinct feature of depending on the particle mass. We show that due to the novel core-halo morphology present in the RAR profile, the allowed particle mass window is narrowed down to $m_s\sim 10-15$ keV, when analyzed within the $\nu$MSM sterile neutrino model. We further discuss on the possible effects in the sterile neutrino parameter-space bounds due to a self-interacting nature of the dark matter candidates.