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Related papers: Millisecond pulsars and the gamma-ray excess in An…

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We study the possibility that an extended cosmic-ray leptonic and/or hadronic halo is at the origin of the large-scale gamma-ray emission detected from the Andromeda Galaxy (M31). We consider a broad ensemble of non-homogeneous diffusion…

High Energy Astrophysical Phenomena · Physics 2021-12-22 Audrey Do , Matthew Duong , Alex McDaniel , Collin O'Connor , Stefano Profumo , Justine Rafael , Connor Sweeney , Washington Vera

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

The new tools of gravitational wave and multi-messenger astronomy allow for the study of astrophysical phenomenon in new ways and enables light to be shed on some of the longest-enduring mysteries of high-energy astrophysics. Among the…

High Energy Astrophysical Phenomena · Physics 2025-01-09 Kayla Bartel , Stefano Profumo

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

Cosmic rays, along with stellar radiation and magnetic fields, are known to make up a significant fraction of the energy density of galaxies such as the Milky Way. When cosmic rays interact in the interstellar medium, they produce gamma-ray…

Pulsed emission from almost one hundred millisecond pulsars (MSPs) has been detected in $\gamma$-rays by the Fermi Large-Area Telescope. The global properties of this population remain relatively unconstrained despite many attempts to model…

High Energy Astrophysical Phenomena · Physics 2018-09-25 R. T. Bartels , T. D. P. Edwards , C. Weniger

The Fermi Large Area Telescope observed an excess in gamma ray emission spectrum coming from the center of the Milky Way galaxy. This data reveals that a light Dark Matter (DM) candidate of mass in the range 31-40 GeV, dominantly decaying…

High Energy Physics - Phenomenology · Physics 2015-06-19 Dilip Kumar Ghosh , Subhadeep Mondal , Ipsita Saha

The Galactic Center Gamma-Ray Excess has a spectrum, angular distribution, and overall intensity that agree remarkably well with that expected from annihilating dark matter particles in the form of a $m_X \sim 50 \, {\rm GeV}$ thermal…

High Energy Astrophysical Phenomena · Physics 2022-09-30 Dan Hooper

We present the results of a population synthesis of radio and gamma-ray millisecond pulsars (MSPs) from the Galactic Disk (GD). Using 92 radio millisecond pulsars detected in 13 radio surveys and 54 Fermi MSPs detected as point sources in…

High Energy Astrophysical Phenomena · Physics 2018-08-29 Peter L. Gonthier , Alice K. Harding , Elizabeth C. Ferrara , Sara E. Frederick , Victoria E. Mohr , Yew-Meng Koh

Over the last few years, the data obtained using the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope has provided new insights on high-energy processes in globular clusters, particularly those involving compact objects…

High Energy Astrophysical Phenomena · Physics 2017-02-22 P. H. Thomas Tam , C. Y. Hui , Albert K H. Kong

Two unresolved questions at galaxy centers, namely the formation of the nuclear star cluster (NSC) and the origin of the gamma-ray excess in the Milky Way (MW) and Andromeda (M31), are both related to the formation and evolution of globular…

Astrophysics of Galaxies · Physics 2023-12-27 Yuan Gao , Hui Li , Xiaojia Zhang , Meng Su , Stephen Chi Yung Ng

Using archival {\it Fermi}-LAT data with a time span of $\sim12$ years, we study the population of Millisecond Pulsars (MSPs) in Globular Clusters (GlCs) and investigate their dependence on cluster dynamical evolution in the Milky Way…

Astrophysics of Galaxies · Physics 2024-01-30 Li Feng , Zhongqun Cheng , Wei Wang , Zhiyuan Li , Yang Chen

An excess of gamma rays has been identified at the centre of the Milky Way, and annihilation of dark matter has been posited as a potential source. This hypothesis faces significant challenges: difficulty characterizing astrophysical…

High Energy Astrophysical Phenomena · Physics 2018-09-05 Hamish A. Clark , Pat Scott , Roberto Trotta , Geraint F. Lewis

The presence of an excess gamma-ray signal toward the Galactic center (GC) has now been well established, and is known as the GC excess. Leading explanations for the signal include mis-modeling of the Galactic diffuse emission along the…

High Energy Astrophysical Phenomena · Physics 2021-03-24 Anne-Katherine Burns , Max Fieg , Christopher M. Karwin , Arvind Rajaraman

The Galactic Center Excess (GCE) is an extended gamma-ray source in the central region of the Galaxy found in Fermi Large Area Telescope (Fermi-LAT) data. One of the leading explanations for the GCE is an unresolved population of…

High Energy Astrophysical Phenomena · Physics 2021-06-15 Harrison Ploeg , Chris Gordon , Roland Crocker , Oscar Macias

The Fermi Large Area Telescope, in collaboration with several groups from the radio community, have had marvellous success at uncovering new gamma-ray millisecond pulsars (MSPs). In fact, MSPs now make up a sizable fraction of the total…

High Energy Astrophysical Phenomena · Physics 2015-05-19 C. Venter , A. K. Harding , T. J. Johnson

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

The Fermi Large Area Telescope (LAT) has revealed a mysterious extended excess of GeV gamma-ray emission around the Galactic Center, which can potentially be explained by unresolved emission from a population of pulsars, particularly…

Understanding the physics of rotation-powered millisecond pulsars (MSPs) presents a number of challenges compared to that of the non-recycled pulsar population. Even though their fast rotation rates can produce high spin-down power and…

High Energy Astrophysical Phenomena · Physics 2022-04-06 Alice K. Harding

Recently, a diffuse emission of 1-100 GeV $\gamma$-rays has been detected from the direction of Andromeda. The emission is centered on the galaxy, and extends for $\sim 100-200$ kpc away from its center. Explaining the extended $\gamma-$ray…

High Energy Astrophysical Phenomena · Physics 2021-06-30 S. Recchia , S. Gabici , F. A. Aharonian , V. Niro