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Related papers: Probing the Cosmic Ray density in the inner Galaxy

200 papers

Galaxy clusters are predicted to produce gamma-rays through cosmic ray interactions and/or dark matter annihilation, potentially detectable by the Fermi Large Area Telescope (Fermi-LAT). We present a new, independent stacking analysis of…

High Energy Astrophysical Phenomena · Physics 2015-06-19 Rhiannon D. Griffin , Xinyu Dai , Christopher S. Kochanek

The $\gamma$-ray emission from stars is induced by the interaction of cosmic rays with stellar atmospheres and photon fields. This emission is expected to come in two components: a stellar disk emission, where $\gamma$-rays are mainly…

High Energy Astrophysical Phenomena · Physics 2021-08-04 Raniere de Menezes , Elena Orlando , Mattia Di Mauro , Andrew Strong

The diffuse Galactic gamma-ray emission is produced by cosmic rays (CRs) interacting with the interstellar gas and radiation field. Measurements by the Energetic Gamma-Ray Experiment Telescope (EGRET) instrument on the Compton Gamma-Ray…

High Energy Astrophysical Phenomena · Physics 2010-04-23 LAT Collaboration

The spectrum and morphology of the diffuse Galactic gamma-ray emission carries valuable information on cosmic ray (CR) propagation. Recent results obtained by analyzing Fermi-LAT data accumulated over seven years of observation show a…

High Energy Astrophysical Phenomena · Physics 2016-08-05 S. Recchia , P. Blasi , G. Morlino

Gamma-ray emission produced by interactions between cosmic rays (CRs) and interstellar gas traces the product of their densities throughout the Milky Way. The outer Galaxy is a privileged target of investigation to separate interstellar…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Luigi Tibaldo , Isabelle A. Grenier , Tsunefumi Mizuno

Recent observations of the diffuse Galactic gamma-ray emission by the Fermi-LAT satellite have shown significant deviations from models which assume the same diffusion properties for cosmic rays (CR) throughout the Galaxy. We explore the…

High Energy Astrophysical Phenomena · Physics 2017-08-17 G. Morlino , M. D'Angelo , P. Blasi , E. Amato

Gamma-ray emission from large structures is useful for tracing the propagation and distribution of cosmic rays throughout our Galaxy. For example, the search for gamma-ray emission from Giant Molecular Clouds may allow us to probe the flux…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Henrike Fleischhack , Hugo Alberto Ayala Solares , Petra Huentemeyer , Matthew Coel

An accurate estimate of the interstellar gas density distribution is crucial to understanding the interstellar medium (ISM) and Galactic cosmic rays (CRs). To comprehend the ISM and CRs in a local environment, a study of the diffuse…

High Energy Astrophysical Phenomena · Physics 2020-02-26 T. Mizuno , S. Abdollahi , Y. Fukui , K. Hayashi , T. Koyama , A. Okumura , H. Tajima , H. Yamamoto

The Galactic Center region is expected to host the largest density of Dark Matter (DM) particles within the Milky Way. Then a relatively large gamma-ray signal would be expected from the possible DM particles annihilation (or decay). We are…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Vincenzo Vitale , Aldo Morselli

A spherical-symmetric gamma-ray emission from the central region of the Galaxy has been recently identified in Fermi-LAT data, and initially associated to dark matter particle annihilations. Guided by the evidence for a high gas density in…

High Energy Astrophysical Phenomena · Physics 2016-01-13 Daniele Gaggero , Marco Taoso , Alfredo Urbano , Mauro Valli , Piero Ullio

Galaxy clusters are the most massive gravitationally bound structures in the Universe. Even if clusters are nearly virialized structures, they undergo merging processes, creating merging shocks, and suffer from feedback from galaxies and…

High Energy Astrophysical Phenomena · Physics 2025-09-22 Judit Pérez-Romero , Mattia di Mauro , Rémi Adam , Miguel Á. Sánchez-Conde , Gabrijela Zaharijas

The gamma-ray sky >100 MeV is dominated by the diffuse emissions from interactions of cosmic rays with the interstellar gas and radiation fields of the Milky Way. Observations of these diffuse emissions provide a tool to study cosmic-ray…

High Energy Astrophysical Phenomena · Physics 2015-06-04 LAT Collaboration

We report an analysis of the interstellar gamma-ray emission from nearby molecular clouds Chamaeleon, R Coronae Australis (R CrA), and Cepheus and Polaris flare regions with the {\it Fermi} Large Area Telescope (LAT). They are among the…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Katsuhiro Hayashi , Tsunefumi Mizuno

Context: Diffuse $\gamma$-ray emission from cosmic ray (CR) protons scattering off the gas in the intracluster and intergalactic medium (ICM and IGM) remains out of reach for current observations. Detecting this emission would provide…

High Energy Astrophysical Phenomena · Physics 2025-10-20 Ludwig M. Böss , Ildar Khabibullin , Daniel Karner , Klaus Dolag , Ulrich P. Steinwandel , Elena Hernandez-Martinez , Jenny G. Sorce

Aims. We use 5 years of Fermi-LAT data towards the Galactic-centre giant molecular cloud complex, Sagittarius B, to test questions of how well-mixed the Galactic component of cosmic rays are and what the level of the cosmic-ray sea in…

High Energy Astrophysical Phenomena · Physics 2015-08-12 Rui-zhi Yang , David I. Jones , Felix Aharonian

EGRET data on the Gamma ray emission from the inner Galaxy have shown a rather flat spectrum, extending to about 50 GeV. It is usually assumed that these gamma-rays arise from the interactions of cosmic ray nuclei with ambient matter.…

Astrophysics · Physics 2007-05-23 Wolfgang Rhode , Torsten A. Ensslin , Peter L. Biermann

Cosmic-ray (CR) sources temporarily enhance the relativistic particle density in their vicinity over the background distribution accumulated from the Galaxy-wide past injection activity and propagation. If individual sources are close…

High Energy Astrophysical Phenomena · Physics 2021-08-18 Guðlaugur Jóhannesson , Troy A. Porter

We present a novel interpretation of the gamma-ray diffuse emission measured by H.E.S.S. in the Galactic Center (GC) region and the Galactic ridge. Our starting base is an updated analysis of PASS8 Fermi-LAT data, which allows to extend…

High Energy Astrophysical Phenomena · Physics 2017-07-27 D. Gaggero , D. Grasso , A. Marinelli , M. Taoso , A. Urbano , S. Ventura

As recently shown, Fermi-LAT measurements of the diffuse gamma-ray emission from the Galaxy favor the presence of a smooth softening in the primary cosmic-ray spectrum with increasing Galactocentric distance. This result can be interpreted…

High Energy Astrophysical Phenomena · Physics 2016-06-22 Daniele Gaggero , Dario Grasso , Antonio Marinelli , Alfredo Urbano , Mauro Valli

We report the results of our study of the energy spectra and absolute fluxes of cosmic rays (CRs) in the Local Galaxy based on a five-year $\gamma$-ray observation with the Fermi Large Area Telescope (LAT) of eight nearby giant molecular…

High Energy Astrophysical Phenomena · Physics 2014-07-03 Rui-zhi Yang , Emma de Oña Wilhelmi , Felix Aharonian