English
Related papers

Related papers: An Anisotropic Propagation Model for Galactic Cosm…

200 papers

Galactic-scale winds are a generic feature of massive galaxies with high star formation rates across a broad range of redshifts. Despite their importance, a detailed physical understanding of what drives these mass-loaded global flows has…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Munier Salem , Greg L. Bryan

We present simulations of the magnetized interstellar medium (ISM) in models of massive star forming (40 Msun / yr) disk galaxies with high gas surface densities (~100 Msun / pc^2) similar to observed star forming high-redshift disks. We…

Astrophysics of Galaxies · Physics 2015-06-17 Michal Hanasz , Harald Lesch , Thorsten Naab , Artur Gawryszczak , Kacper Kowalik , Dominik Wóltański

We measure the three components of velocity dispersion, $\sigma_{R},\sigma_{\theta},\sigma_{\phi}$, for stars within 6 < R < 30 kpc of the Milky Way using a new radial velocity sample from the MMT telescope. We combine our measurements with…

Astrophysics of Galaxies · Physics 2015-11-11 Charles King , Warren R. Brown , Margaret J. Geller , Scott J. Kenyon

We phenomenologically developed a propagation model of high energy galactic cosmic rays. We derived the analytical solutions by adopting the semi-empirical diffusion equation, proposed by Berezinskii {\it et al.}(1990) and the diffusion…

High Energy Astrophysical Phenomena · Physics 2012-02-07 Hideyoshi Arakida , Shuichi Kuramata

Cosmic ray propagation is diffusive because of pitch angle scattering by waves. We demonstrate that if the high-amplitude magnetohydrodynamic turbulence with $\tilde B/\langle B\rangle \sim 1$ is present on top of the mean field gradient,…

High Energy Astrophysical Phenomena · Physics 2015-09-30 Mikhail V. Medvedev , Viktor V. Medvedev

We present 1D cosmic ray transport models, numerically solving equations of pure advection and diffusion for the electrons and calculating synchrotron emission spectra. We find that for exponential halo magnetic field distributions…

Astrophysics of Galaxies · Physics 2016-02-24 Volker Heesen , Ralf-Juergen Dettmar , Marita Krause , Rainer Beck , Yelena Stein

Under nonuniform convection, the distribution of diffusive particles can exhibit dipole and quadrupole anisotropy induced by the fluid inertial and shear force, respectively. These convection-related anisotropies, unlike the Compton-Getting…

High Energy Astrophysical Phenomena · Physics 2022-10-26 Yiran Zhang , Siming Liu , Dejin Wu

Cosmic-ray transport in astrophysical environments is often dominated by the diffusion of particles in a magnetic field composed of both a turbulent and a mean component. This process, which is two-fold turbulent mixing in that the particle…

High Energy Astrophysical Phenomena · Physics 2021-12-14 P. Reichherzer , L. Merten , J. Dörner , J. Becker Tjus , M. J. Pueschel , E. G. Zweibel

We propose that the observed spectral hardening in Galactic cosmic ray fluxes is governed by macroscopic Galactic outflows, such as the eROSITA bubbles, rather than microphysical variations in their scattering properties. Employing a…

High Energy Astrophysical Phenomena · Physics 2026-04-03 Benedikt Schroer

The diffusion coefficients around the pulsar $\gamma$-ray halos are highly suppressed compared with the value in the interstellar medium. It is suggested in the literature that the $\gamma$-ray halos can be explained by a…

High Energy Astrophysical Phenomena · Physics 2023-08-17 Xiao-Jun Bi

Cosmic ray transport on galactic scales depends on the detailed properties of the magnetized, multiphase interstellar medium (ISM). In this work, we post-process a high-resolution TIGRESS magnetohydrodynamic simulation modeling a local…

High Energy Astrophysical Phenomena · Physics 2021-11-24 Lucia Armillotta , Eve C. Ostriker , Yan-Fei Jiang

We calculate the diffusion coefficients of charged cosmic rays (CR) propagating in regular and turbulent magnetic fields. If the magnetic field is dominated by an isotropic turbulent component, we find that CRs reside too long in the…

High Energy Astrophysical Phenomena · Physics 2018-07-24 G. Giacinti , M. Kachelriess , D. V. Semikoz

As a basic characteristic of cosmic ray (CR) propagation, the diffusive halo can advance our understanding of many CR-related studies and indirect dark matter. The method to derive the halo size usually has degeneracy problems thus affected…

High Energy Astrophysical Phenomena · Physics 2021-10-27 Yu-Hua Yao , Bing-Qiang Qiao , Wei Liu , Qiang Yuan , Hong-Bo Hu , Xiao-Jun Bi , Chao-Wen Yang , Yi-Qing Guo

The theory of Galactic Winds, driven by the cosmic-ray pressure gradient, is reviewed both on the magnetohydrodynamic and on the kinetic level. In this picture the magnetic field of the Galaxy above the dense gas disk is assumed to have a…

High Energy Astrophysical Phenomena · Physics 2014-11-06 Heinrich J. Völk

Various studies have implied the existence of a gaseous halo around the Galaxy extending out to 100 kpc. Galactic cosmic rays (CRs) that propagate to the halo, either by diffusion or by convection with the possibly existing large-scale…

High Energy Astrophysical Phenomena · Physics 2019-01-30 Ruo-Yu Liu , Huirong Yan , Xiang-Yu Wang , Shi Shao , Hui Li

The effects of cosmic-ray diffusion and radiative cooling on the structure of the Galactic wind are studied using a steady state approximation. It is known that realistic cooling processes suppress the wind from launching. The effects of…

Astrophysics of Galaxies · Physics 2022-02-16 Jiro Shimoda , Shu-ichiro Inutsuka

Recent advances in understanding of magnetohydrodynamic (MHD) turbulence call for revisions in the picture of cosmic ray transport. In this paper we use recently obtained scaling laws for MHD modes to obtain the scattering frequency for…

Astrophysics · Physics 2009-11-10 Huirong Yan , A. Lazarian

We model the fastest moving (v_tot > 300 km/s) local (D < 3 kpc) halo stars using cosmological simulations and 6-dimensional Gaia data. Our approach is to use our knowledge of the assembly history and phase-space distribution of halo stars…

Astrophysics of Galaxies · Physics 2019-03-13 Alis J. Deason , Azadeh Fattahi , Vasily Belokurov , Wyn Evans , Robert J. Grand , Federico Marinacci , Rudiger Pakmor

Cosmic ray nuclei fluxes are expected to be measured with high precision in the near future. For instance, high quality data on the antiproton component could give important clues about the nature of the astronomical dark matter. A very…

Astrophysics · Physics 2008-11-26 D. Maurin , F. Donato , R. Taillet , P. Salati

Very high intensities of galactic cosmic rays measured by Voyager 1 in the heliosheath appear to be incompatible with the presence of a modulation "wall" near the heliopause produced by a pile up of the heliospheric magnetic field. We…

Space Physics · Physics 2013-02-14 V. Florinski , F. Alouani-Bibi , J. Kota , X. Guo