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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

Dark matter annihilation or decay could have a significant impact on the ionisation and thermal history of the universe. In this paper, we study the potential contribution of dark matter annihilation (s-wave- or p-wave-dominated) or decay…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-14 Hongwan Liu , Tracy R. Slatyer , Jesús Zavala

We present a sample of low-resolution 5-38um Spitzer IRS spectra of the inner few square kiloparsecs of 59 nearby galaxies spanning a large range of star formation properties. A robust method for decomposing mid-infrared galaxy spectra is…

INTEGRAL/SPI has recently observed a strong and extended emission resulting from electron-positron annihilation located in the Galactic center region, consistent with the Galactic bulge geometry, without any counterpart at high gamma-ray…

Astrophysics · Physics 2007-05-23 Stephane Schanne , Michel Casse , Bertrand Cordier , Jacques Paul

A new model of gamma radiation (GR) generated by neutralino annihilation in neutralino stars (NeS) is proposed. Diffuse Galactic and extragalactic GR is calculated for this model and is shown to be in a reasonable agreement with…

Astrophysics · Physics 2009-10-30 A. V. Gurevich , K. P. Zybin

Supersymmetric neutralinos are one of the most promising candidates for the dark matter in the Universe. If they exist, they should make up some fraction of the Milky Way halo. We investigate the fluxes of positrons expected at the Earth…

Astrophysics · Physics 2009-05-12 Edward A. Baltz , Joakim Edsjo

We make a detailed analysis of the indirect diffuse gamma-ray signals from dark matter annihilation in the Galaxy. We include the prompt emission, as well as the emission from inverse Compton scattering whenever the annihilation products…

High Energy Astrophysical Phenomena · Physics 2012-11-14 Steve Blanchet , Julien Lavalle

The Two Micron All Sky Survey, along with the Stellar Population Synthesis Model of the Galaxy, developed in Besancon, is used to calculate the extinction distribution along different lines of sight. By combining many lines of sight, the…

Astrophysics · Physics 2011-04-08 D. J. Marshall , A. C. Robin , C. Reyle , M. Schultheis , S. Picaud

Recent measurements of cosmic-ray electron and positron fluxes by PAMELA and ATIC experiments may indicate the existence of annihilating dark matter with large annihilation cross section. We discuss its possible relation to other…

High Energy Physics - Phenomenology · Physics 2016-11-15 Kazunori Nakayama

The existence of macroscopic objects from antimatter (antistars) is envisaged in some models of baryogenesis. Searches for antistars has been usually carried out in gamma-rays through hadronic annihilation of matter. In astrophysically…

High Energy Astrophysical Phenomena · Physics 2022-03-04 A. E. Bondar , S. I. Blinnikov , A. M. Bykov , A. D. Dolgov , K. A. Postnov

The positron excess observed by the PAMELA experiment may come from dark matter annihilation, if the annihilation cross section is large enough. We show that the dark matter annihilation scenarios to explain the positron excess may also be…

High Energy Physics - Phenomenology · Physics 2014-11-18 Junji Hisano , Masahiro Kawasaki , Kazunori Kohri , Kazunori Nakayama

We calculate the luminosity and energy spectrum of the neutrino emission from electron-positron pair annihilation during the collapse of a supermassive star (${M} \ga 5\times10^4 {M_\odot}$). We then estimate the cumulative flux and energy…

Astrophysics · Physics 2009-10-30 Xiangdong Shi , George M. Fuller

Cross-correlating the gamma-ray background with local galaxy catalogs potentially gives stringent constraints on dark matter annihilation. We provide updated theoretical estimates of sensitivities to the annihilation cross section from…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-27 Shin'ichiro Ando

To study large-scale structure in the Universe a full census of the contents are required. This is even more important when the processes of galaxy formation are being investigated. In the last year the population of distant galaxies that…

Astrophysics · Physics 2009-10-31 Andrew W. Blain

The bulk of the extragalactic background between 10 keV and 10 GeV is likely to be explained by the emission of Seyfert galaxies, type Ia supernovae, and blazars. However, as revealed by the INTEGRAL satellite, the bulge of our galaxy is an…

Electron-positron annihilation largely occurs in local thermal and chemical equilibrium after the neutrinos fall out of thermal equilibrium and during the Big Bang Nucleosynthesis (BBN) epoch. The effects of this process are evident in BBN…

High Energy Physics - Phenomenology · Physics 2020-03-11 Luke C. Thomas , Ted Dezen , Evan B. Grohs , Chad T. Kishimoto

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

The absorption of a high-energy photon from the external cosmic gamma-ray background in the inner neutron star magnetosphere triggers the generation of a secondary electron-positron plasma and gives rise to a lightning - a lengthening and…

High Energy Astrophysical Phenomena · Physics 2011-11-02 Ya. N. Istomin , D. N. Sob'yanin

High-energy collisions of cosmic-ray nuclei with interstellar gas are believed to be the mechanism producing the majority of cosmic ray antiprotons. Due to the kinematics of the process they are created with a nonzero momentum; the…

Astrophysics · Physics 2010-05-28 I. V. Moskalenko , A. W. Strong , J. F. Ormes , M. S. Potgieter

We propose a methodology to perform a self-consistent analysis of the physical properties of the emitting gas of HII galaxies adequate to the data that can be obtained with the XXI century technology. This methodology requires the…

Astrophysics of Galaxies · Physics 2009-01-21 G. F. Hagele , A. I. Diaz , E. Terlevich , E. Perez-Montero , R. Terlevich , M. V. Cardaci