Stellar-like Galactic center excess challenges particle dark matter

Fuente: arXiv
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Autori principali: Manconi, Silvia, Eckner, Christopher, Calore, Francesca, Donato, Fiorenza
Natura: Preprint
Pubblicazione: 2025
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author Manconi, Silvia
Eckner, Christopher
Calore, Francesca
Donato, Fiorenza
author_facet Manconi, Silvia
Eckner, Christopher
Calore, Francesca
Donato, Fiorenza
contents The Galactic Center (GC) is potentially hosting the largest indirect signal from particle dark matter (DM), which in many well-motivated models would produce gamma rays as their final states. However, this region has often been dismissed for DM studies because of the evidence for an unexpected gamma-ray component over astrophysical backgrounds at GeV energies, firstly discovered in the data of the \textit{Fermi} Large Area Telescope (LAT), the so-called Galactic Center Excess (GCE). While this was initially considered to hint at GeV thermal relics, recent work supports a GCE interpretation in terms of a stellar population of millisecond pulsar-like sources in the Galactic bulge. Building on this preference, we re-evaluate the GC as a powerful target for indirect DM searches via gamma rays. This is achieved by combining adaptive template fitting and pixel-count statistical methods to assess the role of sub-threshold point sources in the observed \textit{Fermi}-LAT gamma-ray counts, while minimizing the mismodeling of Galactic diffuse emission backgrounds. In a fully self-consistent way, the gamma-ray data are fitted with a mixed model comprising a DM signal and a stellar bulge, both potentially contributing to the GCE. The space left for signals from weak-scale DM particle annihilations is quantified by extracting 95\% C.L. upper limits on the annihilation cross section, which, depending on the DM density profile, result in stringent limits for masses $\lesssim 300$ GeV. The robustness of our results is supported by tests on simulated data.
format Preprint
id arxiv_https___arxiv_org_abs_2511_03350
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Stellar-like Galactic center excess challenges particle dark matter
Manconi, Silvia
Eckner, Christopher
Calore, Francesca
Donato, Fiorenza
High Energy Physics - Phenomenology
High Energy Astrophysical Phenomena
The Galactic Center (GC) is potentially hosting the largest indirect signal from particle dark matter (DM), which in many well-motivated models would produce gamma rays as their final states. However, this region has often been dismissed for DM studies because of the evidence for an unexpected gamma-ray component over astrophysical backgrounds at GeV energies, firstly discovered in the data of the \textit{Fermi} Large Area Telescope (LAT), the so-called Galactic Center Excess (GCE). While this was initially considered to hint at GeV thermal relics, recent work supports a GCE interpretation in terms of a stellar population of millisecond pulsar-like sources in the Galactic bulge. Building on this preference, we re-evaluate the GC as a powerful target for indirect DM searches via gamma rays. This is achieved by combining adaptive template fitting and pixel-count statistical methods to assess the role of sub-threshold point sources in the observed \textit{Fermi}-LAT gamma-ray counts, while minimizing the mismodeling of Galactic diffuse emission backgrounds. In a fully self-consistent way, the gamma-ray data are fitted with a mixed model comprising a DM signal and a stellar bulge, both potentially contributing to the GCE. The space left for signals from weak-scale DM particle annihilations is quantified by extracting 95\% C.L. upper limits on the annihilation cross section, which, depending on the DM density profile, result in stringent limits for masses $\lesssim 300$ GeV. The robustness of our results is supported by tests on simulated data.
title Stellar-like Galactic center excess challenges particle dark matter
topic High Energy Physics - Phenomenology
High Energy Astrophysical Phenomena
url https://arxiv.org/abs/2511.03350