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Related papers: Advective and diffusive cosmic ray transport in ga…

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We study the propagation of cosmic rays (CRs) through a simulation of magnetohydrodynamic (MHD) turbulence at unprecedented resolution of $10{,}240^3$. We drive turbulence that is subsonic and super-Alfv\'enic, characterized by $\delta…

We present imaging Fabry-Perot observations of Halpha emission in the nearly edge-on spiral galaxy NGC 5775. We have derived a rotation curve and a radial density profile along the major axis by examining position-velocity (PV) diagrams…

Astrophysics · Physics 2009-11-13 G. H. Heald , R. J. Rand , R. A. Benjamin , J. A. Collins , J. Bland-Hawthorn

SOFIA/HAWC+ 154 $\mu$m Far-Infrared polarimetry observations of the well-studied edge-on galaxy NGC 891 are analyzed and compared to simple disk models with ordered (planar) and turbulent magnetic fields. The overall low magnitude and the…

Astrophysics of Galaxies · Physics 2023-05-10 Jin-Ah Kim , Terry Jay Jones , C. Darren Dowell

Recent direct measurements of Galactic cosmic ray spectra by balloon/space-borne detectors reveal spectral hardenings of all major nucleus species at rigidities of a few hundred GV. The all-sky diffuse gamma-ray emissions measured by the…

High Energy Astrophysical Phenomena · Physics 2018-03-21 Yi-Qing Guo , Qiang Yuan

Galactic cosmic rays (CRs) play a crucial role in galaxy formation and evolution by altering gas dynamics and chemistry across multiple scales. Typical numerical simulations of CR transport assume a constant diffusion coefficient for the…

Astrophysics of Galaxies · Physics 2025-10-16 Sarah Thiele , Romain Teyssier

Conventional cosmic-ray propagation models usually assume an isotropic diffusion coefficient to account for the random deflection of cosmic rays by the turbulent interstellar magnetic field. Such a picture is very successful in explaining…

High Energy Astrophysical Phenomena · Physics 2020-03-24 Wei Liu , Su-jie Lin , Hong-bo Hu , Yi-qing Guo , Ai-feng Li

Context. Indirect observations of the cosmic-ray electron (CRE) distribution via synchrotron emission is crucial for deepening the understanding of the CRE transport in the interstellar medium, and in investigating the role of galactic…

High Energy Astrophysical Phenomena · Physics 2023-01-24 Julien Dörner , Patick Reichherzer , Julia Becker Tjus , Volker Heesen

The potential role of magnetic fields and cosmic ray propagation for feedback processes in the early Universe can be probed by studies of local starburst counterparts with an equivalent star-formation rate. Archival data from the WSRT was…

Astrophysics of Galaxies · Physics 2017-10-12 B. Adebahr , M. Krause , U. Klein , M. Wezgowiec , D. J. Bomans , R. -J. Dettmar

Measurement sensitivity in the energetic gamma-ray region has improved considerably, and is about to increase further in the near future, motivating a detailed calculation of high-energy (>100 MeV) and very-high-energy (VHE: >100 GeV)…

High Energy Astrophysical Phenomena · Physics 2015-05-13 Y. Rephaeli , Y. Arieli , M. Persic

Galactic transport models for cosmic rays involve the diffusive motion of these particles in the interstellar medium. Due to the large-scale structured galactic magnetic field this diffusion is anisotropic with respect to the local field…

High Energy Astrophysical Phenomena · Physics 2013-06-07 Frederic Effenberger , Horst Fichtner , Klaus Scherer , Ingo Büsching

We consider the propagation of cosmic rays in turbulent magnetic fields. We use the models of magnetohydrodynamic turbulence that were tested in numerical simulations, in which the turbulence is injected on large scale and cascades to small…

Astrophysics · Physics 2009-11-13 Huirong Yan , A. Lazarian

The pair of large radio lobes in the Virgo cluster, each about 23 kpc in radius, have curiously sharp outer edges where the radio-synchrotron continuum flux declines abruptly. However, just adjacent to this sharp transition, the radio flux…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 William G. Mathews , Fulai Guo

The extended hot X-ray emitting gaseous halo of the Milky Way has an optical depth $\sim1$ for the dominant emission lines of \ion{O}{7} and \ion{O}{8}, which are used to infer the halo properties. To improve on halo gas properties, we…

Astrophysics of Galaxies · Physics 2017-11-15 Yunyang Li , Joel Bregman

A model is introduced, in which the irregularity spectrum of the Galactic magnetic field beyond the dissipation length scale is first a Kolmogorov spectrum $k^{-5/3}$ at small scales $\lambda \, = \, 2 \pi/k$ with $k$ the wave-number, then…

High Energy Astrophysical Phenomena · Physics 2015-11-16 P. L. Biermann , L. I. Caramete , A. Meli , B. N. Nath , E. -S. Seo , V. de Souza , J. Becker Tjus

One of the fundamental issues in cosmic ray physics is to explain the nature of cosmic ray acceleration and propagation mechanisms. Thanks to the precise cosmic ray data measured by recent space experiments, we are able to investigate the…

High Energy Astrophysical Phenomena · Physics 2022-09-20 Yu Wang , Juan Wu , Wei-Cheng Long

The AMS Collaboration has recently released precision data on cosmic ray (CR) leptons and protons at high energies. Interesting progresses have also been made on the measurement of CR nuclei, such as the boron-to-carbon ratio or the lithium…

High Energy Astrophysical Phenomena · Physics 2015-11-02 Nicola Tomassetti

We study the synchrotron radio emission from extra-planar regions of star forming galaxies. We use ideal magneto-hydrodynamical (MHD) simulations of a rotating Milky Way-type disk galaxy with distributed star formation sites for three star…

Astrophysics of Galaxies · Physics 2020-01-08 Aditi Vijayan , Biman B. Nath , Prateek Sharma , Yuri Shchekinov

Fast radio bursts offer the opportunity to place new constraints on the mass and density profile of hot and ionized gas in galactic haloes. We test here the X-ray emission and dispersion measure predicted by different gas profiles for the…

Astrophysics of Galaxies · Physics 2020-06-03 Laura C. Keating , Ue-Li Pen

In the classic picture of standard thin accretion disks, the viscous heating is balanced by the radiative cooling through the diffusion process, and the radiation-pressure-dominated inner disk suffers convective instability. However, recent…

High Energy Astrophysical Phenomena · Physics 2017-05-03 Hong-Yu Gong , Wei-Min Gu

This article aims at establishing new benchmark scenarios for Galactic cosmic-ray propagation in the GV-TV rigidity range, based on fits to the AMS-02 B/C data with the USINE v3.5 propagation code. We employ a new fitting procedure,…

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