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Related papers: Molecular Clouds as the Origin of the Fermi Gamma-…

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Evidence of excess GeV emission nearly coinciding with the Galactic Centre has been interpreted as a possible signature of annihilating dark matter. In this paper, we argue that it seems too early to discard pulsars as a viable explanation…

High Energy Astrophysical Phenomena · Physics 2015-06-17 N. Mirabal

Long-term observations of the Galactic center by Fermi and HESS have revealed a novel phenomenon: the high-energy gamma-ray spectrum from the Galactic center exhibits a double power-law structure. In this study, we propose a new explanation…

High Energy Astrophysical Phenomena · Physics 2025-03-10 Lin Nie , Yi-Qing Guo , Si-Ming Liu

The diffuse galactic EGRET gamma ray data show a clear excess for energies above 1 GeV in comparison with the expectations from conventional galactic models. The excess is seen with the same spectrum in all sky directions, as expected for…

High Energy Physics - Phenomenology · Physics 2009-11-10 W. de Boer

A fundamental question regarding the Galactic Center Excess (GCE) is whether the underlying structure is point-like or smooth. This debate, often framed in terms of a millisecond pulsar or annihilating dark matter (DM) origin for the…

High Energy Astrophysical Phenomena · Physics 2021-01-04 Florian List , Nicholas L. Rodd , Geraint F. Lewis , Ishaan Bhat

Despite decades of direct and indirect searches within the Weakly Interacting Massive Particle (WIMP) framework, no conclusive results have been found in the GeV--TeV range. This has motivated exploring alternatives, including new particles…

High Energy Astrophysical Phenomena · Physics 2025-09-23 A. Salces , P. D. L. T. Luque , M. A. Sánchez Conde

W28 is one of the archetype supernova remnants (SNRs) interacting with molecular clouds. H.E.S.S. observation found four TeV sources which are coincident with the molecular clouds (MCs) around W28, but Fermi LAT detected no prominent GeV…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Hui Li , Yang Chen

Diffuse emission in gamma-rays and neutrinos are produced by the interaction of cosmic rays with the interstellar medium. Below some hundreds of TeV, the sources of these cosmic rays are most likely Galactic. Hence, observations of…

High Energy Astrophysical Phenomena · Physics 2025-09-25 Anton Stall , Philipp Mertsch

The Galactic gamma-ray diffuse emission is currently observed in the GeV-TeV energy range with unprecedented accuracy by the Fermi satellite. Understanding this component is crucial as it provides a background to many different signals such…

High Energy Astrophysical Phenomena · Physics 2015-03-18 Timur Delahaye , Armand Fiasson , Martin Pohl , Pierre Salati

The aim of this work is to improve models for the gamma-ray discrete or small-scale structure related to H2 interstellar gas. Reliably identifying this contribution is important to disentangle gamma-ray point sources from interstellar gas,…

High Energy Astrophysical Phenomena · Physics 2023-07-12 Christopher M. Karwin , Alex Broughton , Simona Murgia , Alexander Shmakov , Mohammadamin Tavakoli , Pierre Baldi

It has been proposed that a recent outburst of cosmic-ray electrons could account for the excess of GeV-scale gamma rays observed from the region surrounding the Galactic Center. After studying this possibility in some detail, we identify…

High Energy Astrophysical Phenomena · Physics 2015-12-09 Ilias Cholis , Carmelo Evoli , Francesca Calore , Tim Linden , Christoph Weniger , Dan Hooper

To understand Galactic objects that emits GeV-TeV emission, a spatial correlation study between the Fermi bright source catalog and TeV source population was carried out in Tam et al. (2010), finding that a significant number of very…

High Energy Astrophysical Phenomena · Physics 2011-11-07 P. Tam , S. Wagner

The Milky Way's Galactic Center harbors a gamma-ray excess that is a candidate signal of annihilating dark matter. Dwarf galaxies remain predominantly dark in their expected commensurate emission. In this work we quantify the degree of…

High Energy Astrophysical Phenomena · Physics 2018-05-16 Ryan E. Keeley , Kevork N. Abazajian , Anna Kwa , Nicholas L. Rodd , Benjamin R. Safdi

Cold dark matter models predict the existence of a large number of substructures within dark matter halos. If the cold dark matter consists of weakly interacting massive particles, their annihilation within these substructures could lead to…

Cosmology and Nongalactic Astrophysics · Physics 2012-12-10 Jiaxin Han , Carlos S. Frenk , Vincent R. Eke , Liang Gao , Simon D. M. White , Alexey Boyarsky , Denys Malyshev , Oleg Ruchayskiy

Various theoretical models predict the existence of extended $\gamma$-ray halo around normal galaxies that could be produced by interactions of cosmic rays with the circumgalactic medium or by annihilation or decay of hypothetical dark…

High Energy Astrophysical Phenomena · Physics 2026-04-03 M. S. Pshirkov , B. A. Nizamov

We analyze publicly available Fermi-LAT high-energy gamma-ray data and confirm the existence of clear spectral feature peaked at E=130GeV. Scanning over the Galaxy we identify several disconnected regions where the observed excess…

High Energy Physics - Phenomenology · Physics 2012-10-31 Elmo Tempel , Andi Hektor , Martti Raidal

Fermi Large Area Telescope data reveal an excess of GeV gamma rays from the direction of the Galactic Center and bulge. Several explanations have been proposed for this excess including an unresolved population of millisecond pulsars (MSPs)…

High Energy Astrophysical Phenomena · Physics 2017-08-15 Harrison Ploeg , Chris Gordon , Roland Crocker , Oscar Macias

The strongest experimental evidence for dark matter is the Galactic Center gamma-ray excess observed by the Fermi telescope and even predicted prior to discovery as a potential dark matter signature via WIMP dark matter self-annihilations.…

High Energy Astrophysical Phenomena · Physics 2025-08-11 Moorits Mihkel Muru , Joseph Silk , Noam I. Libeskind , Stefan Gottloeber , Yehuda Hoffman

The three major large-scale, diffuse $\gamma$-ray structures of the Milky Way are the Galactic disk, a bulge-like GeV excess towards the Galactic center, and the Fermi bubble. Whether such structures can also be present in other normal…

High Energy Astrophysical Phenomena · Physics 2019-04-03 Li Feng , Zhiyuan Li , Meng Su , Pak-Hin T. Tam , Yang Chen

The existence of dark matter (DM) is supported by various macroscopic observations, but its microscopic nature remains elusive. The Galactic Center GeV gamma-ray excess (GCE) has been a leading candidate signal for particle DM annihilation.…

High Energy Astrophysical Phenomena · Physics 2026-03-03 Ming-Yu Lei , Bei Zhou , Xiaoyuan Huang

A new population of millisecond pulsars is a long-standing proposed explanation for the excess of GeV-scale gamma rays emanating from the region surrounding the center of the Milky Way (the "Galactic Center excess"). We examine several…

High Energy Astrophysical Phenomena · Physics 2023-07-06 Jack T. Dinsmore , Tracy R. Slatyer