English
Related papers

Related papers: Cosmic-ray Acceleration and Propagation

200 papers

We show that massive young star clusters may be possible candidates that can accelerate Galactic cosmic rays (CRs) in the range of $10^7\hbox{--}10^9$ GeV (between the `knee' and `ankle'). Various plausible scenarios such as acceleration at…

High Energy Astrophysical Phenomena · Physics 2024-02-26 Sourav Bhadra , Satyendra Thoudam , Biman B Nath , Prateek Sharma

Precise measurements of the energy spectra of cosmic rays (CRs) show various kinds of features deviating from single power-laws, which give very interesting and important implications on their origin and propagation. Previous measurements…

The origin of Galactic CRs up the knee energy remains unanswered and provides strong motivation for the study of gamma-ray sources at energies above 10 TeV. We discuss recent results from ground-based gamma-ray Cherenkov imaging systems at…

Astrophysics · Physics 2007-05-23 G. Rowell , F. Aharonian , A. Plyasheshnikov

Cosmic rays are charged energetic particles that permeate the interstellar medium. Their sizeable energy share and penetration power makes them essential players in the dynamical and chemical processes that rule Galactic evolution, such as…

High Energy Astrophysical Phenomena · Physics 2026-03-17 Giada Peron , Sarah Recchia , Stefano Menchiari , Alexandre Marcowith , Andrei Bykov , Martin Pohl , Elena Amato

Given the success of the first meeting of "Cosmic Ray Origin - Beyond the Standard Models" (CRBTSM 2014), it was decided to hold a second meeting of this international conference. In these introductory remarks, we rehearse the motivation…

High Energy Astrophysical Phenomena · Physics 2018-05-30 Omar Tibolla , Roger D. Blandford

Several lines of evidence point to a relationship between gamma-ray bursts (GRBs) and the high mass stars that explode as supernovae. Arguments that GRB sources accelerate cosmic rays (CRs) are summarized. High-energy neutrino detection…

Astrophysics · Physics 2009-11-10 C. D. Dermer , A. Atoyan

It is presumed that the observed cosmic rays up to about $3\times 10^{18}$ eV are of Galactic origin, the particles being the ones which are found in the composition of the stellar winds of stars that explode as supernova into the…

Astrophysics · Physics 2007-05-23 Adrian Sabin Popescu

The secondary-to-primary B/C ratio is widely used to study the cosmic ray (CR) propagation processes in the Galaxy. It is usually assumed that secondary nuclei such as Li-Be-B are entirely generated by collisions of heavier CR nuclei with…

High Energy Astrophysical Phenomena · Physics 2012-07-24 N. Tomassetti , F. Donato

It is widely believed that supernova remnants are the best candidate sources for the observed cosmic ray flux up to the knee, i.e. up to ~PeV energies. Indeed, the gamma-ray spectra of some supernova remnants can be well explained by…

High Energy Astrophysical Phenomena · Physics 2015-09-02 Nils Nierstenhoefer , Philipp Graeser , Florian Schuppan , Julia Becker Tjus

Since the discovery of cosmic rays (CRs) over a century ago, their origin remains an open question. Galactic CRs with energy up to the knee ($10^{15}$ eV) are considered to originate from supernova remnants, but this scenario has recently…

High Energy Astrophysical Phenomena · Physics 2022-01-10 D. Kantzas , S. Markoff , M. Lucchini , C. Ceccobello , V. Grinberg , R. M. T. Connors , P. Uttley

The origin of the highest energy cosmic rays remains an enigma. They offer a window to new physics, including tests of physical laws relevant to their propagation and interactions, at energies unattainable by terrestrial accelerators. They…

High Energy Astrophysical Phenomena · Physics 2011-02-02 Sayan Chakraborti , Alak Ray , Alicia Soderberg , Abraham Loeb , Poonam Chandra

We study the production of cosmic rays (CRs) in supernova remnants (SNRs), including the reacceleration of background galactic cosmic rays (GCRs) - thus refining the early considerations by Blandford & Ostriker (1980) and Wandel et al.…

Astrophysics · Physics 2007-05-23 E. G. Berezhko , L. T. Ksenofontov , V. S. Ptuskin , V. N. Zirakashvili , H. J. Voelk

Cosmic rays (CRs) may be used to infer properties of intervening cosmic magnetic fields. Conversely, understanding the effects of magnetic fields on the propagation of high-energy CRs is crucial to elucidate their origin. In the present…

High Energy Astrophysical Phenomena · Physics 2018-11-08 R. Alves Batista , E. M. de Gouveia Dal Pino , K. Dolag , S. Hussain

Explicitly time-dependent, nonlinear kinetic theory of cosmic ray (CR) acceleration in supernova remnants (SNRs) has been used to investigate the properties of the very large SNR RX J0852.0-4622. The available observations do not clearly…

Astrophysics · Physics 2007-08-01 E. G. Berezhko , G. Pühlhofer , H. J. Völk

Modern X-ray and $\gamma$-ray instruments are revealing a growing class of Galactic non-thermal sources whose emission centroids are measurably offset from the nearest plausible sites of cosmic ray (CR) acceleration. Such "displaced"…

High Energy Astrophysical Phenomena · Physics 2026-03-13 Manami Roy , Mark R. Krumholz , Roland M. Crocker , Todd A. Thompson

Our Galaxy is the largest nuclear interaction experiment which we know, because of the interaction between cosmic ray particles and the interstellar material. Cosmic rays are particles, which have been accelerated in the Galaxy or in…

Astrophysics · Physics 2011-04-15 Peter L. Biermann

Particle acceleration in the dynamically evolving environment of Supernova Remnants is discussed in the framework of a genuinely time-dependent nonlinear theory, assuming spherical symmetry. As a consequence the dependence of injection on…

Astrophysics · Physics 2007-05-23 H. J. Voelk

The origin of the knee in the energy spectrum of cosmic rays is an outstanding problem in astroparticle physics. Numerous mechanisms have been proposed to explain the structure in the all-particle spectrum. In the article basic ideas of…

Astrophysics · Physics 2015-06-24 Joerg R. Hoerandel

In the past few years, gamma-ray astronomy has entered a golden age. At TeV energies, only a handful of sources were known a decade ago, but the current generation of ground-based imaging atmospheric Cherenkov telescopes has increased this…

High Energy Astrophysical Phenomena · Physics 2017-08-23 Marianne Lemoine-Goumard

The optical and near-IR emission from some classes of supernovae (SNe), including Type IIn and possibly some super-luminous SNe, is likely powered by a collision between the SN ejecta and dense circumstellar material (CSM). We argue that…

High Energy Astrophysical Phenomena · Physics 2014-04-21 Kohta Murase , Todd A. Thompson , Eran O. Ofek
‹ Prev 1 8 9 10 Next ›