An All-Sky Search for Moving Gamma-Ray Sources with Fermi-LAT
Abstract
Nearby compact gamma-ray sources can move appreciably during the Fermi-LAT mission and thus evade searches that assume a stationary sky. Compact dark matter halos, dark matter spikes around primordial black holes (PBH), and evaporating PBH provide potential examples. We perform a novel all-sky search for steady point sources moving at 0.25 deg/yr-0.8deg/yr in ten years of 1-100 GeV Fermi-LAT data. For a transverse speed of 200 km/s, this angular range probes distances of roughly 3.0×103 AU to 9.7×103 AU. We find 577 candidate tracks, consistent with 533±27.0 tracks in time-scrambled skies. We place a model-independent 90% upper limit of 80.8 recovered signal tracks. At peak calibrated sensitivity, this corresponds to fewer than 123 steady, full-sky sources with an incident E−2 photon spectrum. We give the calibrated detection efficiency of the search to steady point sources and use it to derive illustrative constraints on both evaporating PBHs and PBHs surrounded by annihilating dark matter halos.
Related
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BibTeX
@misc{lai2026allsky,
title = {{An All-Sky Search for Moving Gamma-Ray Sources with Fermi-LAT}},
author = {Dou Lai and James Unwin},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.14058},
eprint = {2610.14058},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.14058},
}
RIS
TY - UNPB
TI - An All-Sky Search for Moving Gamma-Ray Sources with Fermi-LAT
AU - Dou Lai
AU - James Unwin
PY - 2026
DA - 2026/10/06
PB - arXiv
DO - 10.48550/arxiv.2610.14058
UR - https://arxiv.org/abs/2610.14058
AB - Nearby compact gamma-ray sources can move appreciably during the Fermi-LAT mission and thus evade searches that assume a stationary sky. Compact dark matter halos, dark matter spikes around primordial black holes (PBH), and evaporating PBH provide potential examples. We perform a novel all-sky search for steady point sources moving at 0.25 deg/yr-0.8deg/yr in ten years of 1-100 GeV Fermi-LAT data. For a transverse speed of 200 km/s, this angular range probes distances of roughly 3.0×10^3 AU to 9.7×10^3 AU. We find 577 candidate tracks, consistent with 533±27.0 tracks in time-scrambled skies. We place a model-independent 90% upper limit of 80.8 recovered signal tracks. At peak calibrated sensitivity, this corresponds to fewer than 123 steady, full-sky sources with an incident E^−2 photon spectrum. We give the calibrated detection efficiency of the search to steady point sources and use it to derive illustrative constraints on both evaporating PBHs and PBHs surrounded by annihilating dark matter halos.
ER -