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Related papers: Constraining dark matter by the 511 keV line

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The intense 0.511 MeV gamma-ray line emission from the Galactic Center observed by INTEGRAL requires a large annihilation rate of nonrelativistic positrons. If these positrons are injected at even mildly relativistic energies, higher-energy…

Astrophysics · Physics 2008-11-26 John F. Beacom , Hasan Yuksel

The origin and properties of the source of positrons annihilating in the Galactic Center is still a mystery. One of the criterion, which may discriminate between different mechanisms of positron production there, is the positron energy…

Astrophysics of Galaxies · Physics 2015-05-14 D. O. Chernyshov , K. -S. Cheng , V. A. Dogiel , C. -M. Ko , W. -H. Ip

MeV dark matter (DM) particles annihilating or decaying to electron-positron pairs cannot, in principle, be observed via local cosmic-ray (CR) measurements because of the shielding solar magnetic field. In this letter, we take advantage of…

High Energy Astrophysical Phenomena · Physics 2017-07-19 Mathieu Boudaud , Julien Lavalle , Pierre Salati

Recent indirect searches of dark matter using gamma-ray, radio, and cosmic-ray data have provided some stringent constraints on annihilating dark matter. In this article, we propose a new indirect method to constrain annihilating dark…

High Energy Physics - Phenomenology · Physics 2023-09-12 Man Ho Chan , Chak Man Lee

We present a map of 511 keV electron-positron annihilation emission, based on data accumulated with the SPI spectrometer aboard ESA's INTEGRAL gamma-ray observatory, that covers approximately 95% of the celestial sphere. 511 keV line…

Compton Gamma Ray Observatory, OSSE, SMM, TGRS, balloon and recent INTEGRAL data reveal a feature of the 0.511 MeV annihilation radiation of the Galactic Center with a flux of approximately 5x 10^{-4}~0.511 MeV photons cm^{-2} s^{-1}. We…

Astrophysics · Physics 2009-11-13 Lev Titarchuk , Pascal Chardonnet

The WMAP experiment has revealed an excess of microwave emission from the region around the center of our Galaxy. It has been suggested that this signal, known as the ``WMAP Haze'', could be synchrotron emission from relativistic electrons…

Astrophysics · Physics 2008-11-26 Dan Hooper , Douglas P. Finkbeiner , Gregory Dobler

From 16 years of INTEGRAL/SPI $\gamma$-ray observations, we derive bounds on annihilating light dark matter particles in the halo of the Milky Way up to masses of about 300 MeV. We test four different spatial templates for the dark matter…

High Energy Astrophysical Phenomena · Physics 2024-02-29 Thomas Siegert , Francesca Calore , Pasquale Dario Serpico

Cosmic-ray positrons have long been considered a powerful probe of dark matter annihilation. In particular, myriad studies of the unexpected rise in the positron fraction have debated its dark matter or pulsar origins. In this paper, we…

High Energy Astrophysical Phenomena · Physics 2022-01-07 Isabelle John , Tim Linden

Well-motivated models of dark matter often result in a population of electrons and positrons within galaxies produced through dark matter annihilation -- usually in association with gamma rays. As they diffuse through galactic magnetic…

High Energy Physics - Phenomenology · Physics 2024-02-23 Mitchell J. Weikert , Matthew R. Buckley

AMS-02 provided the unprecedented statistics in the measurement of the positron fraction from cosmic rays. That may offer a unique opportunity to distinguish the positron spectrum coming from various dark matter (DM) annihilation channels,…

High Energy Physics - Phenomenology · Physics 2016-02-17 Yu-Heng Chen , Kingman Cheung , Po-Yan Tseng

The reported excess of $\gamma$-rays, emitted from an extended region around the galactic center, has a distribution and rate suggestive of an origin in dark matter (DM) annihilations. The conventional annihilation channels into standard…

High Energy Physics - Phenomenology · Physics 2015-06-23 Marat Freytsis , Dean J. Robinson , Yuhsin Tsai

If dark matter is unstable and the mass is within GeV-TeV regime, its decays produce high-energy photons that give contribution to the extragalactic gamma-ray background (EGRB). We constrain dark matter decay by analyzing the 50-month EGRB…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Shin'ichiro Ando , Koji Ishiwata

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

Recent gamma-ray and radio observations provide stringent constraints for annihilating dark matter. The current $2\sigma$ lower limits of dark matter mass can be constrained to $\sim 100$ GeV for thermal relic annihilation cross section. In…

High Energy Astrophysical Phenomena · Physics 2021-01-05 Man Ho Chan , Chak Man Lee

Hawking evaporation of primordial black hole (PBH), with mass $3\times 10^{-17} \lesssim M_{\rm PBH}/M_\odot \lesssim 7\times 10^{-17}$ and fractional abundance $0.01 \lesssim f_{\rm PBH} \lesssim 0.5$, well reproduces 511 keV gamma-ray…

High Energy Physics - Phenomenology · Physics 2023-08-17 Po-Yan Tseng , Yu-Min Yeh

Recent COMPTEL data analysis reveals a $\sim$ 2 MeV continuum excess whose spatial distribution closely matches the long-standing 511 keV line observed by INTEGRAL/SPI, indicating a common population of low-energy positrons that is…

High Energy Physics - Phenomenology · Physics 2026-01-16 Shyam Balaji , Damon Cleaver , Pedro De la Torre Luque

The AMS-02 collaboration has recently presented measurements of excellent quality of the cosmic electron and positron fluxes as well as the positron fraction. We use the measurements of the positron flux to derive, for the first time,…

High Energy Physics - Phenomenology · Physics 2014-04-02 Alejandro Ibarra , Anna S. Lamperstorfer , Joseph Silk

We study multi-component dark matter scenarios and the Galactic 511 keV $\gamma$-ray emission line signal in the framework of a local, dark $U(1)_D$ extension of the Standard Model. A light vector dark matter particle associated with the…

High Energy Physics - Phenomenology · Physics 2025-06-04 Sarif Khan , Jinsu Kim , Jongkuk Kim , Pyungwon Ko
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