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Related papers: Diffuse gamma-rays from galactic halos

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The enormous range of X-ray luminosities among elliptical galaxies with similar optical luminosities can be attributed to large scatter and systematic variations in the dark halo mass determined from X-ray observations. The mean halo mass…

The recently published GALFA-HI Compact Cloud Catalogue lists 20 neutral hydrogen clouds that might pinpoint previously undiscovered high-latitude dwarf galaxies. Detection of an associated gamma-ray dark matter signal could provide a route…

High Energy Astrophysical Phenomena · Physics 2015-06-15 N. Mirabal

Many star-forming galaxies and those hosting active galactic nuclei (AGN) show evidence of massive outflows of material in a variety of phases including ionized, neutral atomic, and molecular. Molecular outflows in particular have been the…

High Energy Astrophysical Phenomena · Physics 2023-02-15 Alex McDaniel , Marco Ajello , Chris Karwin

This article reviews the present status of high energy gamma-ray astronomy at energies above 30 MeV. Observations in the past decade using both space- and ground-based experiments have been primarily responsible for giving a tremendous…

Astrophysics · Physics 2010-12-03 R. Mukherjee

The high-energy diffuse gamma-ray emission and neutrino emission are expected from the Galactic plane, generated by hadronuclear interactions between cosmic rays (CR) and interstellar medium (ISM). Therefore, measurements of these diffuse…

High Energy Astrophysical Phenomena · Physics 2024-03-19 Kai Yan , Ruo-Yu Liu , Rui Zhang , Chao-Ming Li , Qiang Yuan , Xiang-Yu Wang

The Fermi-LAT data accumulated over 7 years of {\gamma}-ray observations, together with the high resolution gas (CO & HI) and the dust opacity maps, are used to study the emissivity of {\gamma}-rays induced by interactions of cosmic rays…

High Energy Astrophysical Phenomena · Physics 2016-06-22 Rui-zhi Yang , Felix Aharonian , Carmelo Evoli

The attenuation of very high energy gamma rays by pair production on the Galactic interstellar radiation field has long been thought of as negligible. However, a new calculation of the interstellar radiation field consistent with…

Astrophysics · Physics 2009-11-11 I. V. Moskalenko , T. A. Porter , A. W. Strong

Galactic diffuse gamma-ray flux measured by the Tibet AS$\gamma$ experiment and the total Galactic gamma-ray flux measured by Large High Altitude Air Shower Observatory (LHAASO) are found to be consistent, within the statistical and…

Adopting a recent calculation of the Galactic interstellar radiation field, we calculate the attenuation of the very high energy gamma rays from the Galactic sources. The infra-red radiation background near the Galactic Center is very…

Astrophysics · Physics 2009-11-13 Jian-Li Zhang , Xiao-Jun Bi , Hong-Bo Hu

We show that the baryonic gas content of the halo of our galaxy can be probed by performing a multipole expansion on the distribution of diffuse background gamma-ray emission. While the monopole moment (isotropic background) can be used to…

Astrophysics · Physics 2009-09-25 Xiaochun Luo , J. Silk

We study diffuse gamma-ray emission at intermediate Galactic latitudes measured by the Fermi Large Area Telescope with the aim of searching for a signal from dark matter annihilation or decay. In the absence of a robust dark matter signal,…

High Energy Astrophysical Phenomena · Physics 2013-04-10 G. Zaharijas , J. Conrad , A. Cuoco , Z. Yang

The universe is filled with a diffuse and isotropic extragalactic background of gamma-ray radiation, containing roughly equal energy flux per decade in photon energy between 3 MeV-100 GeV. The origin of this background is one of the…

Astrophysics · Physics 2011-05-05 Abraham Loeb , Eli Waxman

The propagation of $\gamma$ rays over very large distances provides new insights on the intergalactic medium and on fundamental physics. On their path to the Earth, $\gamma$ rays can annihilate with diffuse infrared or optical photons of…

High Energy Astrophysical Phenomena · Physics 2016-07-20 Dieter Horns , Agnieszka Jacholkowska

Cosmic rays fill up the entire volume of galaxies, providing an important source of heating and ionisation of the interstellar medium, and may play a significant role in the regulation of star formation and galactic evolution. Diffuse…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Troy A. Porter

We use the GALPROP model for cosmic-ray propagation to obtain a new estimate of the Galactic component of gamma rays, and show that away from the Galactic plane it gives an accurate prediction of the observed EGRET intensities in the energy…

Astrophysics · Physics 2009-11-10 A. W. Strong , I. V. Moskalenko , O. Reimer

In the frame of indirect dark matter searches we investigate the flux of high-energy $\gamma$-ray photons produced by annihilation of dark matter in caustics within our Galaxy under the hypothesis that the bulk of dark matter is composed of…

Astrophysics · Physics 2009-11-11 Lidia Pieri , Enzo Branchini

Inverse Compton scattering appears to play a more important role in the diffuse Galactic continuum emission than previously thought, from MeV to GeV energies. We compare models having a large inverse Compton component with EGRET data, and…

Astrophysics · Physics 2007-05-23 I. V. Moskalenko , A. W. Strong

The EGRET results for gamma-ray intensities in and near the Galactic Plane have been analysed in some detail. Attention has been concentrated on energies above 1 GeV and the individual intensities in a $4^\circ$ longitude bin have been…

Astrophysics · Physics 2009-11-11 A. D. Erlykin , A. W. Wolfendale

Galactic diffuse TeV gamma-ray emission is produced by the interaction of high-energy cosmic-ray particles with matter and radiation in our Galaxy. The measurement of Galactic diffuse TeV gamma-ray emission would provide strong constraints…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Hao Zhou , Chang Dong Rho , Giacomo Vianello

Cold, dense gas clouds have been proposed as a major component of the Galactic dark matter; such clouds can be revealed by the gamma-ray emission which arises from cosmic-rays interacting with the gas. If this dark matter component is…

Astrophysics · Physics 2008-11-26 Mark Walker , Masaki Mori , Michiko Ohishi