AXIS Could Have Accessed Dark Matter Decays
Abstract
The Advanced X-ray Imaging Satellite (AXIS) was a mission concept designed to improve upon the sensitivity and spatial resolution of the Chandra X-ray Observatory and XMM-Newton. Although AXIS was not selected for implementation, the concept study defined a mature instrument design with low-background, arcsecond imaging over the $0.3−10$ keV energy range, a large effective area, and a wide field of view. These capabilities provide a useful benchmark for the dark matter decay sensitivity of future X-ray observatories. We estimate the reach of a future AXIS-like instrument for narrow photon lines from decaying keV-scale dark matter, including axion-like particles and sterile neutrinos. For Galactic center observations, we find projected lifetime sensitivities of order 1031 s, improving upon existing limits by up to an order of magnitude over part of the keV mass range.
Related
- Constraints with CMB lensing on dark matter decays to massive decay products
- How long could volcanic plumes persist in the Venus atmosphere?
- What we have not learned about the dark energy equation of state
- Can wormholes have vanishing Love numbers?
- What We Have Learned from NICER About Neutron Star Radii
BibTeX
@misc{foster2026axis,
title = {{AXIS Could Have Accessed Dark Matter Decays}},
author = {Joshua W. Foster and Inci Karaaslan and Gordan Krnjaic and Nimrod Shapir},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2608.28738},
eprint = {2608.28738},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.28738},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - AXIS Could Have Accessed Dark Matter Decays
AU - Joshua W. Foster
AU - Inci Karaaslan
AU - Gordan Krnjaic
AU - Nimrod Shapir
PY - 2026
DA - 2026/10/22
PB - arXiv
DO - 10.48550/arxiv.2608.28738
UR - https://arxiv.org/abs/2608.28738
AB - The Advanced X-ray Imaging Satellite (AXIS) was a mission concept designed to improve upon the sensitivity and spatial resolution of the Chandra X-ray Observatory and XMM-Newton. Although AXIS was not selected for implementation, the concept study defined a mature instrument design with low-background, arcsecond imaging over the $0.3−10$ keV energy range, a large effective area, and a wide field of view. These capabilities provide a useful benchmark for the dark matter decay sensitivity of future X-ray observatories. We estimate the reach of a future AXIS-like instrument for narrow photon lines from decaying keV-scale dark matter, including axion-like particles and sterile neutrinos. For Galactic center observations, we find projected lifetime sensitivities of order 10^31 s, improving upon existing limits by up to an order of magnitude over part of the keV mass range.
ER -