On the Energy Distribution of the Galactic Center Excess' Sources

Fuente: arXiv
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Main Authors: List, Florian, Park, Yujin, Rodd, Nicholas L., Schoen, Eve, Wolf, Florian
Format: Preprint
Published: 2025
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author List, Florian
Park, Yujin
Rodd, Nicholas L.
Schoen, Eve
Wolf, Florian
author_facet List, Florian
Park, Yujin
Rodd, Nicholas L.
Schoen, Eve
Wolf, Florian
contents The Galactic Center Excess (GCE) remains one of the defining mysteries uncovered by the Fermi $γ$-ray Space Telescope. Although it may yet herald the discovery of annihilating dark matter, weighing against that conclusion are analyses showing the spatial structure of the emission appears more consistent with a population of dim point sources. Technical limitations have restricted prior analyses to studying the point-source hypothesis purely spatially. All spectral information that could help disentangle the GCE from the complex and uncertain astrophysical emission was discarded. We demonstrate that a neural network-aided simulation-based inference approach can overcome such limitations and thereby confront the point source explanation of the GCE with spatial and spectral data. The addition is profound: energy information drives the putative point sources to be significantly dimmer, indicating either the GCE is truly diffuse in nature or made of an exceptionally large number of sources. Quantitatively, for our best fit background model, the excess is essentially consistent with Poisson emission as predicted by dark matter. If the excess is instead due to point sources, our median prediction is ${\cal O}(10^5)$ sources in the Galactic Center, or more than 35,000 sources at 90% confidence, both significantly larger than the hundreds of sources preferred by earlier point-source analyses of the GCE.
format Preprint
id arxiv_https___arxiv_org_abs_2507_17804
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle On the Energy Distribution of the Galactic Center Excess' Sources
List, Florian
Park, Yujin
Rodd, Nicholas L.
Schoen, Eve
Wolf, Florian
High Energy Astrophysical Phenomena
Cosmology and Nongalactic Astrophysics
Instrumentation and Methods for Astrophysics
Machine Learning
High Energy Physics - Phenomenology
The Galactic Center Excess (GCE) remains one of the defining mysteries uncovered by the Fermi $γ$-ray Space Telescope. Although it may yet herald the discovery of annihilating dark matter, weighing against that conclusion are analyses showing the spatial structure of the emission appears more consistent with a population of dim point sources. Technical limitations have restricted prior analyses to studying the point-source hypothesis purely spatially. All spectral information that could help disentangle the GCE from the complex and uncertain astrophysical emission was discarded. We demonstrate that a neural network-aided simulation-based inference approach can overcome such limitations and thereby confront the point source explanation of the GCE with spatial and spectral data. The addition is profound: energy information drives the putative point sources to be significantly dimmer, indicating either the GCE is truly diffuse in nature or made of an exceptionally large number of sources. Quantitatively, for our best fit background model, the excess is essentially consistent with Poisson emission as predicted by dark matter. If the excess is instead due to point sources, our median prediction is ${\cal O}(10^5)$ sources in the Galactic Center, or more than 35,000 sources at 90% confidence, both significantly larger than the hundreds of sources preferred by earlier point-source analyses of the GCE.
title On the Energy Distribution of the Galactic Center Excess' Sources
topic High Energy Astrophysical Phenomena
Cosmology and Nongalactic Astrophysics
Instrumentation and Methods for Astrophysics
Machine Learning
High Energy Physics - Phenomenology
url https://arxiv.org/abs/2507.17804