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The recent detection of $\gamma$-rays with energy up to 10 TeV from dense regions surrounding some Supernova Remnants (SNR) provides strong, though still not conclusive, evidence that the nucleonic component of galactic Cosmic Rays is…

Astrophysics · Physics 2009-11-11 Vincenzo Cavasinni , Dario Grasso , Luca Maccione

The theory of diffusive particle acceleration explains the spectral properties of the cosmic rays below energies of approx. 10^6 GeV as produced at strong shocks in supernova remnants (SNR's). To supply the observed flux of cosmic rays, a…

Astrophysics · Physics 2007-05-23 U. D. J. Gieseler , T. W. Jones , Hyesung Kang

Supernovae remnants (SNRs) represent a major feedback source from stars on the interstellar medium of galaxies. During the latest stage of supernovae explosions, shock waves produced by the initial blast modify the chemistry of gas and…

A group of middle-aged mixed-morphology (MM) supernova remnants (SNRs) interacting with molecular clouds (MC) has been discovered as strong GeV gamma-ray emitters by Large Area Telescope on board Fermi Gamma Ray Space Telescope (Fermi-LAT).…

High Energy Astrophysical Phenomena · Physics 2018-03-08 Tülün Ergin , Aytap Sezer , Lab Saha , Pratik Majumdar , Anshu Chatterjee , Arif Bayırlı , E. Nihal Ercan

Context: The supernova remnant (SNR) G35.6-0.4 shows a non-thermal radio shell, however, no {\gamma}-ray or X-ray counterparts have been found for it thus far. One TeV source, HESS J1858+020, was found near the SNR and this source is…

High Energy Astrophysical Phenomena · Physics 2021-02-22 Y. Cui , Y. Xin , S. Liu , P. H. T. Tam , G. Puehlhofer , H. Zhu

We present an analytical model of $\Sigma-D$ relation for supernova remnants (SNRs) evolving in a clumpy medium. The model and its approximations were developed using the hydrodynamic simulations of SNRs in environments of low-density…

Astrophysics of Galaxies · Physics 2024-09-13 Petar Kostić , Bojan Arbutina , Branislav Vukotić , Dejan Urošević

Recent EGRET observations of the diffuse Galactic gamma-ray emission reveal a spectrum which is incompatible with the assumption that the cosmic ray spectra measured locally hold throughout the Galaxy: the spectrum above 1 GeV, where the…

Astrophysics · Physics 2009-11-07 I. Büsching , M. Pohl , R. Schlickeiser

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…

We report on the investigation of a very high energy (VHE), Galactic gamma-ray source recently discovered at >50GeV using the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope. This object, 2FHL J1703.4-4145, displays…

High Energy Astrophysical Phenomena · Physics 2020-12-02 J. Eagle , S. Marchesi , M. Ajello , D. Castro , A. Vendrasco

The nature of the recently detected HE and VHE gamma-ray emission of Tycho's supernova remnant (SNR) is studied. A nonlinear kinetic theory of cosmic ray (CR) acceleration in supernova remnants (SNRs) is employed to investigate the…

High Energy Astrophysical Phenomena · Physics 2015-01-13 E. G. Berezhko , L. T. Ksenofontov , H. J. Voelk

Abbreviated Abstract: A kinetic model of particle acceleration in supernova remnants (SNRs) is extended to study the cosmic ray (CR) and associated high energy gamma-ray production during SN shock propagation through the inhomogeneous…

Astrophysics · Physics 2007-05-23 Evgeny G. Berezhko , Heinrich J. Voelk

Supernova remnants (SNRs) are one of the most energetic astrophysical events and are thought to be the dominant source of Galactic cosmic rays (CRs). A recent report on observations from the Fermi satellite has shown a signature of pion…

High Energy Astrophysical Phenomena · Physics 2015-08-26 Soonyoung Roh , Shu-ichiro Inutsuka , Tsuyoshi Inoue

Supernova remnants (SNRs) are believed to be capable of accelerating cosmic rays (CRs) to PeV energies. SNR G106.3+2.7 is a prime PeVatron candidate. It is formed by a head region, where the pulsar J2229+6114 and its boomerang-shaped pulsar…

We have analysed the Fermi LAT data on the SNR G73.9+0.9. We have confirmed a previous detection of high-energy gamma-rays from this source at a high significance of $\simeq 12\sigma$. The observed spectrum shows a significant curvature,…

Diffuse emission in gamma-rays and neutrinos are produced by the interaction of cosmic rays with the interstellar medium. Below some hundreds of TeV, the sources of these cosmic rays are most likely Galactic. Hence, observations of…

High Energy Astrophysical Phenomena · Physics 2025-09-25 Anton Stall , Philipp Mertsch

Energetic gamma rays (GeV to TeV photon energy) have been detected toward several supernova remnants (SNR) associated with molecular clouds. If the gamma rays are produced mainly by hadronic processes rather than leptonic processes like…

High Energy Astrophysical Phenomena · Physics 2012-05-16 F. Schuppan , J. K. Becker , J. H. Black , S. Casanova

Supernova remnant (SNR)\,W28 is well known for its classic hadronic scenario, in which the TeV cosmic rays (CRs) released at the early stage of this mid-aged SNR are illuminating nearby molecular clouds (MCs). Overwhelming evidences have…

High Energy Astrophysical Phenomena · Physics 2018-06-15 Yudong Cui , Paul K. H. Yeung , P. H. Thomas Tam , Gerd Puehlhofer

In this contribution we will discuss recent results concerning the intensity and the angular distribution of the gamma-ray and neutrino emissions as should be originated from the hadronic scattering of cosmic rays (CR) with the interstellar…

Astrophysics · Physics 2007-08-02 C. Evoli , D. Grasso , L. Maccione

We revisit the signatures from collisions of cosmic-rays on sub-GeV dark matter (DM) in the Milky Way. In addition to the upscattered DM component that can be probed by existing DM and neutrino experiments widely discussed, we examine the…

High Energy Astrophysical Phenomena · Physics 2020-11-09 Gang Guo , Yue-Lin Sming Tsai , Meng-Ru Wu , Qiang Yuan

Cosmic rays are mostly composed of protons accelerated to relativistic speeds. When those protons encounter interstellar material, they produce neutral pions which in turn decay into gamma rays. This offers a compelling way to identify the…

High Energy Astrophysical Phenomena · Physics 2022-08-17 LAT Collaboration , S. Abdollahi , F. Acero , M. Ackermann , L. Baldini , J. Ballet , G. Barbiellini , D. Bastieri , R. Bellazzini , B. Berenji , A. Berretta , E. Bissaldi , R. D. Blandford , R. Bonino , P. Bruel , S. Buson , R. A. Cameron , R. Caputo , P. A. Caraveo , D. Castro , G. Chiaro , N. Cibrario , S. Ciprini , J. Coronado-Blázquez , M. Crnogorcevic , S. Cutini , F. D'Ammando , S. De Gaetano , N. Di Lalla , F. Dirirsa , L. Di Venere , A. Domínguez , S. J. Fegan , A. Fiori , H. Fleischhack , A. Franckowiak , Y. Fukazawa , P. Fusco , V. Gammaldi , F. Gargano , D. Gasparrini , F. Giacchino , N. Giglietto , F. Giordano , M. Giroletti , T. Glanzman , D. Green , I. A. Grenier , M. -H. Grondin , S. Guiriec , M. Gustafsson , A. K. Harding , E. Hays , J. W. Hewitt , D. Horan , X. Hou , G. Jóhannesson , T. Kayanoki , M. Kerr , M. Kuss , S. Larsson , L. Latronico , M. Lemoine-Goumard , J. Li , F. Longo , F. Loparco , P. Lubrano , S. Maldera , D. Malyshev , A. Manfreda , G. Martí-Devesa , M. N. Mazziotta , I. Mereu , P. F. Michelson , N. Mirabal , W. Mitthumsiri , T. Mizuno , M. E. Monzani , A. Morselli , I. V. Moskalenko , E. Nuss , N. Omodei , M. Orienti , E. Orlando , J. F. Ormes , D. Paneque , Z. Pei , M. Persic , M. Pesce-Rollins , R. Pillera , H. Poon , T. A. Porter , G. Principe , S. Rainò , R. Rando , B. Rani , M. Razzano , S. Razzaque , A. Reimer , O. Reimer , T. Reposeur , M. Sánchez-Conde , P. M. Saz Parkinson , L. Scotton , D. Serini , C. Sgrò , E. J. Siskind , G. Spandre , P. Spinelli , K. Sueoka , D. J. Suson , H. Tajima , D. Tak , J. B. Thayer , D. F. Torres , E. Troja , J. Valverde , Z. Wadiasingh , K. Wood , G. Zaharijas