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Related papers: Diffuse Galactic Gamma Rays from Shock-Accelerated…

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We study particle acceleration in strongly turbulent pair plasmas using novel 3D Particle-in-Cell simulations, featuring particle injection from an external heat bath and diffusive escape. We demonstrate the formation of steady-state,…

High Energy Astrophysical Phenomena · Physics 2025-07-10 Evgeny A. Gorbunov , Daniel Grošelj , Fabio Bacchini

Motivated by the discovery of the non-thermal Fermi bubble features both below and above the Galactic plane, we investigate a scenario in which these bubbles are formed through Galacto-centric outflow. Cosmic rays (CR) both diffusing and…

High Energy Astrophysical Phenomena · Physics 2017-01-11 Andrew M. Taylor , Gwenael Giacinti

Diffusive shock acceleration (DSA) at relativistic shocks is expected to be an important acceleration mechanism in a variety of astrophysical objects including extragalactic jets in active galactic nuclei and gamma ray bursts. These sources…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Matthew G. Baring , Errol J. Summerlin

Gamma-ray data from Fermi-LAT reveal a bi-lobular structure extending up to 50 degrees above and below the galactic centre, which presumably originated in some form of energy release there less than a few million years ago. It has been…

High Energy Astrophysical Phenomena · Physics 2011-08-26 Philipp Mertsch , Subir Sarkar

In almost any scenario for 'cosmological' gamma-ray bursts (and in many models where they originate in our own Galaxy), the initial energy density is so large that the resulting relativistic plasma expands with $v\sim c$ producing a blast…

Astrophysics · Physics 2009-10-22 P. Meszaros , M. J. Rees

Massive protostars have associated bipolar outflows with velocities of hundreds of km s$^{-1}$. Such outflows can produce strong shocks when interact with the ambient medium leading to regions of non-thermal radio emission. We aim at…

High Energy Astrophysical Phenomena · Physics 2015-05-14 V. Bosch-Ramon , G. E. Romero , A. T. Araudo , J. M. Paredes

Galactic diffuse continuum gamma-ray emission is intricately related to cosmic-ray physics and radio astronomy. We describe recent results from an approach which endeavours to take advantage of this. Information from cosmic-ray composition…

Astrophysics · Physics 2010-12-13 A. W. Strong , I. V. Moskalenko , O. Reimer

The Tibet ASgamma experiment just reported their measurement of sub-PeV diffuse gamma ray emission from the Galactic disk, with the highest energy up to 957 TeV. These gamma-rays are most likely the hadronic origin by cosmic ray interaction…

High Energy Astrophysical Phenomena · Physics 2021-04-09 Bing-Qiang Qiao , Wei Liu , Meng-Jie Zhao , Xiao-Jun Bi , Yi-Qing Guo

The diffuse TeV emission detected from the inner $\sim2^\circ$ of the Galaxy appears to be strongly correlated with the distribution of molecular gas along the Galactic ridge. Although it is not yet entirely clear whether the origin of the…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Fulvio Melia , Marco Fatuzzo

Context. The diffusive shock acceleration mechanism has been widely accepted as the acceleration mechanism for galactic cosmic rays. While self-consistent hybrid simulations have shown how power-law spectra are produced, detailed…

High Energy Astrophysical Phenomena · Physics 2015-06-04 M. Wolff , R. C. Tautz

A new numerical model of particle propagation in the Galaxy has been developed, which allows the study of cosmic-ray and gamma-ray production and propagation in 2D or 3D, including a full reaction network. This is a further development of…

Astrophysics · Physics 2009-11-06 A. W. Strong , I. V. Moskalenko

The origin of cosmic rays in our Galaxy remains a subject of active debate. While supernova remnant shocks are often invoked as the sites of acceleration, it is now widely accepted that the difficulties of such sources in reaching PeV…

High Energy Astrophysical Phenomena · Physics 2021-03-24 Giovanni Morlino , Pasquale Blasi , Enrico Peretti , Pierre Cristofari

We report calculations of cosmic-ray proton, nuclei, antiproton, electron and positron energy spectra within a "two-halo model" of diffusive transport. The two halos represent a simple, physically consistent generalization of the standard…

High Energy Astrophysical Phenomena · Physics 2015-10-20 Nicola Tomassetti

The diffuse gamma-ray emission between 10 and 1000 TeV from the Galactic plane was recently measured by the Large High Altitude Air Shower Observatory (LHAASO). These observations will help tremendously in constraining the propagation and…

High Energy Astrophysical Phenomena · Physics 2023-11-06 Rui Zhang , Xiaoyuan Huang , Zhi-Hui Xu , Shiping Zhao , Qiang Yuan

Galactic cosmic rays (CR) are particles presumably accelerated in supernova remnant shocks that propagate in the interstellar medium up to the densest parts of molecular clouds, losing energy and their ionisation efficiency because of the…

High Energy Astrophysical Phenomena · Physics 2016-05-25 M. Padovani , A. Marcowith , P. Hennebelle , K. Ferrière

The supernova paradigm for the origin of galactic cosmic rays has been deeply affected by the development of the non-linear theory of particle acceleration at shock waves. Here we discuss the implications of applying such theory to the…

High Energy Astrophysical Phenomena · Physics 2015-03-13 D. Caprioli , E. Amato , P. Blasi

It is well accepted today that diffusive acceleration in shocks results to the cosmic ray spectrum formation. This is in principle true for non-relativistic shocks, since there is a detailed theory covering a large range of their properties…

Astrophysics · Physics 2007-08-13 A. Meli , A. Mastichiadis

An extensive program for the calculation of galactic cosmic-ray propagation has been developed. Primary and secondary nucleons, primary and secondary electrons, secondary positrons and antiprotons are included. Fragmentation and energy…

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

In a previous study (Maurin et al., 2001), we explored the set of parameters describing diffusive propagation of cosmic rays (galactic convection, reacceleration, halo thickness, spectral index and normalization of the diffusion…

Astrophysics · Physics 2009-11-07 David Maurin , Richard Taillet , Fiorenza Donato

One of the most exciting discoveries of recent years is a pair of gigantic gamma-ray emission regions, the so-called Fermi bubbles, above and below the Galactic center. The bubbles, discovered by the Fermi space telescope, extend up to…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Satyendra Thoudam