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Related papers: Cosmological Shocks in Eulerian Simulations: Main …

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We present a sample of 20 massive galaxy clusters with total virial masses in the range of 6 10^14 M_sol<M(vir)< 2 10^15M_sol, re-simulated with a customized version of the 1.5. ENZO code employing Adaptive Mesh Refinement. This technique…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Franco Vazza , Gianfranco Brunetti , Claudio Gheller , Riccardo Brunino

Theoretical studies of cosmic ray particle acceleration in the first-order Fermi process at relativistic shocks are reviewed. At the beginning we discuss the acceleration processes acting at mildly relativistic shock waves. An essential…

Astrophysics · Physics 2007-05-23 Michal Ostrowski

We have examined the properties of shock waves in simulations of large scale structure formation for two cosmological scenarios (a SCDM and a LCDM with Omega =1). Large-scale shocks result from accretion onto sheets, filaments and Galaxy…

We review two decades of progress using the Enzo hydrodynamic cosmology code to simulate the Cosmic Dawn, a period of roughly 1 billion years beginning with the formation of the first stars in the universe, and ending with cosmic…

Astrophysics of Galaxies · Physics 2018-10-09 Michael L. Norman , Britton Smith , James Bordner

Galaxy clusters grow by gas accretion, mostly from mergers of substructures, which release powerful shock waves into cosmic plasmas and convert a fraction of kinetic energy into thermal energy, amplification of magnetic fields and into the…

High Energy Astrophysical Phenomena · Physics 2019-03-11 A. M. Bykov , F. Vazza , J. A. Kropotina , K. P. Levenfish , F. B. S. Paerels

There is an observational correlation between astrophysical shocks and non-thermal particle distributions extending to high energies. As a first step toward investigating the possible feedback of these particles on the shock at the…

High Energy Astrophysical Phenomena · Physics 2012-01-31 Thomas Stroman , Martin Pohl , Jacek Niemiec , Antoine Bret

Particle acceleration in collisionless plasma systems is a central question in astroplasma and astroparticle physics. The structure of the acceleration regions, electron-ion energy equilibration, preacceleration of particles at shocks to…

High Energy Astrophysical Phenomena · Physics 2020-02-19 Martin Pohl , Masahiro Hoshino , Jacek Niemiec

We present the BACCO project, a simulation framework specially designed to provide highly-accurate predictions for the distribution of mass, galaxies, and gas as a function of cosmological parameters. In this paper, we describe our main…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-04 Raul E. Angulo , Matteo Zennaro , Sergio Contreras , Giovanni Aricò , Marcos Pellejero-Ibañez , Jens Stücker

We study the first-order Fermi acceleration process at parallel shock waves by means of Monte Carlo simulations. A 'realistic' model of the magnetic field turbulence is applied involving sinusoidal waves imposed on the background mean field…

Astrophysics · Physics 2007-05-23 Jacek Niemiec , Michal Ostrowski

Possible formulations of the problem of cosmic rays acceleration in the interstellar galactic medium are considered with the use of fractional differential equations. The applied technique has been physically justified. A Fermi result has…

Astrophysics of Galaxies · Physics 2011-05-19 V. V. Uchaikin

Some general features of cosmic ray acceleration are summarized along with some inferences that can be drawn concerning the origin of the UHE component. The UHE luminosity density is found to be similar to that derived for GeV cosmic rays…

Astrophysics · Physics 2010-12-03 R. D. Blandford

Cosmic rays (CRs) play a decisive role within our own Galaxy. They provide partial pressure support against gravity, they trace past energetic events such as supernovae, and they reveal the underlying structure of the baryonic matter…

Astrophysics · Physics 2009-11-11 Torsten A. Ensslin , Christoph Pfrommer , Volker Springel , Martin Jubelgas

We investigate numerically the contribution to the cosmic gamma-ray background from cosmic-rays ions and electrons accelerated at intergalactic shocks associated with cosmological structure formation. We show that the kinetic energy of…

Astrophysics · Physics 2008-11-26 Francesco Miniati

We construct a model for cosmic ray acceleration from protostellar accretion shocks and calculate the resulting cosmic ray ionization rate within star-forming molecular clouds. We couple a protostar cluster model with an analytic accretion…

Astrophysics of Galaxies · Physics 2018-07-25 Brandt A. L. Gaches , Stella S. R. Offner

Structure formation shocks are believed to be the largest accelerators of cosmic rays in the Universe. However, little is still known about their efficiency in accelerating relativistic electrons and protons as a function of their…

High Energy Astrophysical Phenomena · Physics 2020-07-01 Serena Banfi , Franco Vazza , Denis Wittor

This lecture gives a short introduction to different methods used in cosmology. The focus is on major features of N-body simulations: equations, main numerical techniques, effects of resolution, and methods of halo identification.

Astrophysics · Physics 2007-05-23 Anatoly Klypin

Bow shocks generated from the interaction of winds from massive runaway stars with the interstellar medium have been shown to be prominent particle accelerators through recent $\gamma$-ray and radio synchrotron observations. Here, we study…

High Energy Astrophysical Phenomena · Physics 2025-10-15 Keito Watanabe , Stefanie Walch , Tim-Eric Rathjen , Jonathan Mackey , Pierre Nürnberger , Philipp Girichidis

Weak shocks in the intracluster medium may accelerate cosmic-ray protons and cosmic-ray electrons differently depending on the angle between the upstream magnetic field and the shock normal. In this work, we investigate how shock obliquity…

High Energy Astrophysical Phenomena · Physics 2016-12-07 Denis Wittor , Franco Vazza , Marcus Brüggen

We have developed a novel computer code designed to follow the evolution of cosmic-ray modified shocks, including the full momentum dependence of the particles for a realistic diffusion coefficient model. In this form the problem is…

Astrophysics · Physics 2009-10-31 Hyesung Kang , T. W. Jones , R. J. LeVeque , K. M. Shyue

The process of cosmic ray acceleration up to energies in excess of $10^{20}$ eV at relativistic shock waves with large Lorentz factors, $\Gamma \gg 1$ requires $\sim \Gamma^2$ particle energy gains at single reflections from the shock (cf.…

Astrophysics · Physics 2016-08-30 J. Bednarz , M. Ostrowski