Searching for Particle Dark Matter with eROSITA Early Data

Abstract

Many well motivated dark matter (DM) particle candidates can decay into detectable X-ray photons. We analyze the Final Equatorial Depth Survey (eFEDS) data from eROSITA early data release to search for unidentified X-ray lines that could indicate DM signals. Having discovered no anomalous signal, we set limits on DM decay rate in mass range between 1.8-18 keV, and constrain the parameter space of two DM particles: sterile neutrino and axion-like particles. Finally we also study the projected sensitivity of eROSITA full sky search, showing that eROSITA all-sky survey is expected to set the most stringent limits in the soft X-ray band.

Comments: 12+3 pages, 7+2 figures. v3 updated to match version accepted by PRD: redone GC and all-sky projection; added appendix B checking different diffuse sky models; added details and fixed typos; results & conlusions unchanged