Papers › Long-Exposure NuSTAR Constraints on Decaying Dark Matter in the Galactic Halo

Long-Exposure NuSTAR Constraints on Decaying Dark Matter in the Galactic Halo

11 Jul 2022arXiv:2207.04572links table onlyarchive 2025-07-28

Brandon M. Roach, Steven Rossland, Kenny C. Y. Ng, Kerstin Perez, John F. Beacom, Brian W. Grefenstette, Shunsaku Horiuchi, Roman Krivonos, Daniel R. Wik

The archive published only this paper's code-link row. Authors, date and abstract are from arXiv's metadata (CC0), read from the Kaggle arXiv metadata snapshot of 2026-09-12 where its title matched the archive's; the title is the archive's.

We present two complementary NuSTAR x-ray searches for keV-scale dark matter decaying to mono-energetic photons in the Milky Way halo. In the first, we utilize the known intensity pattern of unfocused stray light across the detector planes -- the dominant source of photons from diffuse sources -- to separate astrophysical emission from internal instrument backgrounds using ∼7-Ms/detector deep blank-sky exposures. In the second, we present an updated parametric model of the full NuSTAR instrument background, allowing us to leverage the statistical power of an independent ∼20-Ms/detector stacked exposures spread across the sky. Finding no evidence of anomalous x-ray lines using either method, we set limits on the active-sterile mixing angle sin²(2θ) for sterile-neutrino masses 6--40 keV. The first key result is that we strongly disfavor a ∼7-keV sterile neutrino decaying into a 3.5-keV photon. The second is that we derive leading limits on sterile neutrinos with masses ∼15--18 keV and ∼25--40 keV, reaching or extending below the Big Bang Nucleosynthesis limit. In combination with previous results, the parameter space for the Neutrino Minimal Standard Model (νMSM) is now nearly closed.

PaperPDFCode

Code

roachb/nustar-blanksky officialmentioned in papermentioned on GitHub report

Repository list and official/mentioned flags are the archive's, frozen 2025-07-28. Reachability, where shown, is from one Syntology probe window (2026-09-16 to 2026-09-18); repositories not probed show nothing. GitHub stars are not tracked.

Code Syntology ran Syntology

Not run by Syntology. Nothing on this page verifies that the listed code works.

Results from the paper archive 2025-07-28

No leaderboard rows for this paper in the archive.

Report a problem or propose a change · a person checks every report against the paper or source before anything changes; decisions are listed on /corrections