English
Related papers

Related papers: A Fresh Look at Diffuse Gamma-ray Emission from th…

200 papers

We describe the properties of the blazars detected by EGRET and summarize the results on the calculations of the evolution and luminosity function of these sources. Of the large number of possible origins of extragalactic diffuse gamma-ray…

Astrophysics · Physics 2009-10-31 R. Mukherjee , J. Chiang

We present quantitative statistical evidence for a $\gamma$-ray emission halo surrounding the Galaxy. Maps of the emission are derived. EGRET data were analyzed in a wavelet-based non-parametric hypothesis testing framework, using a model…

The Galactic gamma-ray diffuse emission (GDE) is emitted by cosmic rays (CRs), ultra-relativistic protons and electrons, interacting with gas and electromagnetic radiation fields in the interstellar medium. Here we present the analysis of…

The EGRET excess in the diffuse galactic gamma ray data above 1 GeV shows all the features expected from Dark Matter WIMP Annihilation: a)it is present and has the same spectrum in all sky directions, not just in the galactic plane. b) The…

Astrophysics · Physics 2007-05-23 W. de Boer

The Galactic diffuse soft gamma-ray (30-800 keV) emission has been measured from the Galactic Center by the HIREGS balloon-borne germanium spectrometer to determine the spectral characteristics and origin of the emission. The resulting…

Astrophysics · Physics 2009-10-31 S. E. Boggs , R. P. Lin , S. Slassi-Sennou , W. Coburn , R. M. Pelling

We present a new Fermi-LAT analysis of the Galactic-center excess (GCE) designed to substantially reduce the dominant systematic uncertainties associated with interstellar-emission and source modeling in the inner Galaxy. Using an optimized…

High Energy Astrophysical Phenomena · Physics 2026-05-29 Mattia Di Mauro

We describe the role of GeV gamma-ray observations with GLAST-LAT (Gamma-ray Large Area Space Telescope - Large Area Telescope) in identifying interaction sites of cosmic-ray proton (or hadrons) with interstellar medium (ISM). We expect to…

The Fermi Collaboration has recently updated their analysis of gamma rays from the center of the Galaxy. They reconfirm the presence of an unexplained emission feature which is most prominent in the region of $1-10$ GeV, known as the…

High Energy Physics - Phenomenology · Physics 2018-01-11 Abraham Achterberg , Melissa van Beekveld , Sascha Caron , Germán A. Gómez-Vargas , Luc Hendriks , Roberto Ruiz de Austri

The high energy gamma ray sources provided by experiment EGRET on the Compton Gamma Ray Observatory are examined, testing Project GRAND's ability to detect primary gamma rays by means of studying secondary muons. There is ~1.5% chance that…

Astrophysics · Physics 2007-05-23 J. Carpenter , S. Desch , T. F. Lin , J. Poirier , A. Roesch

Since the launch of the Fermi Gamma-ray Space Telescope on 11 June 2008, significant detections of high energy emission have been reported only in six Gamma-ray Bursts (GRBs) until now. In this work we show that the lack of detection of a…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-29 Yi-Zhong Fan

Measuring the diffuse Galactic gamma-ray flux in the TeV range is difficult for ground-based gamma-ray telescopes because of the residual cosmic-ray background, which is higher than the gamma-ray flux by several orders of magnitude. Its…

High Energy Astrophysical Phenomena · Physics 2020-01-22 A. Neronov , D. V. Semikoz

The HEGRA-IACT-system with a FoV of ~1.5 deg radius has been used for surveying one quater of the Galactic disc in respect to point sources, moderately extended sources and for diffuse emission in the energy range above 1 TeV. In total 140…

After more than six and half years in orbit, the ESA space observatory INTEGRAL has provided new, exciting results in the soft gamma-ray energy range (from a few keV to a few MeV). With the discovery of about 700 hard X-Ray sources, it has…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-28 P. Ubertini , A. Corsi , S. Foley , S. McGlynn , G. De Cesare , A. Bazzano

Gamma-Ray Bursts (GRBs) have been detected at GeV energies by EGRET and models predict emission at > 100 GeV. Milagro is a wide field (2 sr) high duty cycle (> 90 %) ground based water Cherenkov detector that records extensive air showers…

Astrophysics · Physics 2009-11-13 Pablo M. Saz Parkinson

The perspective of the detectability of Galactic dark matter subhaloes on the Fermi satellite is investigated in this work. Under the assumptions that dark matter annihilation accounts for the "GeV excess" of the Galactic diffuse…

Astrophysics · Physics 2014-11-18 Qiang Yuan , Xiao-Jun Bi , Juan Zhang

Observations of diffuse Galactic gamma-ray spectrum by the EGRET instrument reveal an excess above ~ 1 GeV over the expected gamma-ray spectrum calculated under the assumption that the locally observed cosmic-ray (CR) spectra represent the…

Astrophysics · Physics 2009-11-11 Thoudam Satyendra

Recent gamma-ray observations have detected photons up to energies of a few PeV. These highly energetic gamma rays are emitted by the most powerful sources in the Galaxy. Propagating over astrophysical distances, gamma rays might interact…

High Energy Astrophysical Phenomena · Physics 2025-04-18 Gaetano Di Marco , Rafael Alves Batista , Miguel Ángel Sánchez-Conde

Simulations of Galactic CR transport were performed with the software GALPROP, with the resulting gamma-ray flux calculated up to the PeV regime. The impact of altering parameters such as the number and distribution of CR sources, the…

High Energy Astrophysical Phenomena · Physics 2025-04-29 Peter Marinos

Galactic microquasars are certainly one of the most recent additions to the field of high energy astrophysics and have attracted increasing interest over the last decade. However, the high energy part of the spectrum of microquasars is the…

Astrophysics · Physics 2007-05-23 Josep M. Paredes

Population studies of unidentified EGRET sources suggest that there exist at least three different populations of galactic gamma-ray sources. One of these populations is formed by young objects distributed along the galactic plane with a…

Astrophysics · Physics 2009-11-10 V. Bosch-Ramon , G. E. Romero , J. M. Paredes