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Related papers: Bremsstrahlung gamma rays from light Dark Matter

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The diffuse gamma ray emission from astrophysical backgrounds in our Galaxy and the signal due to the annihilation or decay of Dark Matter (DM) in the Galactic Halo are expected to have a substantially different morphology and spectral…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Gabrijela Zaharijas , Alessandro Cuoco , Zhaoyu Yang , Jan Conrad

Dark matter (DM) particles decaying in the Galactic halo can inject energetic $e^\pm$ that inverse-Compton scatter (ICS) solar photons into $\gamma$-rays, producing a diffuse and extended halo of emission around the Sun. We present the…

High Energy Astrophysical Phenomena · Physics 2026-04-02 Maximilian Detering , Shyam Balaji

The role of bremsstrahlung in the emission from hot accretion flows around slowly accreting supermassive black holes is not thoroughly understood. In order to appraise the importance of bremsstrahlung relative to other radiative processes,…

High Energy Astrophysical Phenomena · Physics 2020-07-29 R. Yarza , G. N. Wong , B. R. Ryan , C. F. Gammie

Dark matter annihilating in our Galaxy's halo and elsewhere in the universe is expected to generate a diffuse flux of gamma rays, potentially observable with next generation satellite-based experiments, such as GLAST. In this article, we…

Astrophysics · Physics 2009-11-13 Dan Hooper , Pasquale D. Serpico

A GeV gamma-ray excess has possibly been individuated in Fermi-LAT data from the Galactic Center and interpreted in terms of Dark Matter (DM) annihilations, either in hadronic (essentially $b\bar{b}$) or leptonic channels. In order to test…

High Energy Physics - Phenomenology · Physics 2015-06-22 Marco Cirelli , Daniele Gaggero , Gaëlle Giesen , Marco Taoso , Alfredo Urbano

With the Fermi-LAT data quite a few research groups have reported a spatially extended GeV $\gamma$-ray excess surrounding the Galactic Center (GC). The physical origin of such a GeV excess is still unclear and one interesting possibility…

High Energy Physics - Phenomenology · Physics 2016-06-22 Ming-Yang Cui , Cun Zhang , Hong-Shi Zong

An upper limit on the total annihilation cross section of dark matter (DM) has recently been derived from the observed atmospheric neutrino background. We show that comparable bounds are obtained for DM masses around the TeV scale by…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Kachelriess , P. D. Serpico

We study the gamma rays observed by the Fermi Gamma Ray Space Telescope from the direction of the Galactic Center and find that their angular distribution and energy spectrum are well described by a dark matter annihilation scenario. In…

High Energy Physics - Phenomenology · Physics 2009-11-11 Lisa Goodenough , Dan Hooper

Utilizing the Fermi measurement of the gamma-ray spectrum toward the Galactic Center, we derive some of the strongest constraints to date on the dark matter (DM) lifetime in the mass range from hundreds of MeV to above an EeV. Our…

High Energy Physics - Phenomenology · Physics 2019-06-24 Timothy Cohen , Kohta Murase , Nicholas L. Rodd , Benjamin R. Safdi , Yotam Soreq

Recently, a preliminary spectrum from the Fermi Gamma-ray Space Telescope has been presented for the inner galaxy (-30 < l < 30, -5 < b < 5), as well as the galactic center (-1 < l < 1, -1< b < 1). We consider the implications of these data…

High Energy Astrophysical Phenomena · Physics 2009-07-29 Ilias Cholis , Gregory Dobler , Douglas P. Finkbeiner , Lisa Goodenough , Tracy R. Slatyer , Neal Weiner

We analyze the recently published Fermi-LAT diffuse gamma-ray measurements in the context of leptonically annihilating or decaying dark matter (DM) with the aim to explain simultaneously the isotropic diffuse gamma-ray and the PAMELA, Fermi…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Gert Hütsi , Andi Hektor , Martti Raidal

Prompt emissions from TeV blazars pair produce off the extragalactic background light and the highly energetic resulting pair beams then cascade through inverse Compton scattering to give rise to secondary gamma-rays. Such reprocessed…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-02 Oindrila Ghosh , Sankalan Bhattacharyya

Sub-GeV dark matter particles can annihilate or decay producing e^\pm pairs which upscatter the low-energy photon fields in the Galaxy and generate an X-ray emission (via the Inverse Compton effect). Using X-ray data from XMM-Newton,…

High Energy Physics - Phenomenology · Physics 2025-07-18 Marco Cirelli , Nicolao Fornengo , Jordan Koechler , Elena Pinetti , Brandon M. Roach

We calculate the effects of velocity-dependent dark matter annihilation cross sections on the intensity of the extragalactic gamma-ray background. Our formalism does not assume a locally thermal distribution of dark matter particles in…

High Energy Physics - Phenomenology · Physics 2010-12-09 Sheldon Campbell , Bhaskar Dutta , Eiichiro Komatsu

We study the capabilities of the Fermi-LAT instrument on board of the Fermi mission to constrain particle dark matter properties, as annihilation cross section, mass and branching ratio into dominant annihilation channels, with gamma-ray…

High Energy Astrophysical Phenomena · Physics 2017-02-22 Nicolas Bernal , Sergio Palomares-Ruiz

Galactic weak-scale Dark Matter (DM) particles annihilating into lepton-rich channels not only produce gamma-rays via prompt radiation but also generate abundant energetic electrons and positrons, which subsequently emit through…

High Energy Physics - Phenomenology · Physics 2025-10-09 Marco Cirelli , Arpan Kar

Dark matter annihilation in Galactic substructure will produce diffuse gamma-ray emission of remarkably constant intensity across the sky, making it difficult to disentangle this Galactic dark matter signal from the extragalactic gamma-ray…

High Energy Astrophysical Phenomena · Physics 2010-04-15 Jennifer M. Siegal-Gaskins , Vasiliki Pavlidou

For Majorana dark matter, gauge boson bremsstrahlung plays an important role in enhancing an otherwise helicity-suppressed s-wave annihilation cross-section. This is well known for processes involving a radiated photon or gluon together…

High Energy Physics - Phenomenology · Physics 2015-06-17 Feng Luo , Tevong You

We study the prospects for detecting gamma-rays from Dark Matter (DM) annihilations in enhancements of the DM density (mini-spikes) around intermediate-mass black holes with masses in the range $10^2 \lsim M / \msun \lsim 10^6$. Focusing on…

Astrophysics · Physics 2008-11-26 Gianfranco Bertone , Andrew R. Zentner , Joseph Silk

The annihilation of light dark matter was recently advocated as a possible explanation of the large positron injection rate at the Galactic center deduced from observations by the SPI spectrometer aboard INTEGRAL. The modelling of internal…

Astrophysics · Physics 2008-11-26 P. Sizun , M. Casse , S. Schanne