English
Related papers

Related papers: Constraining cosmic ray acceleration in young star…

200 papers

We study the propagation of mildly-relativistic cosmic rays (CRs) in multiphase interstellar medium environments with conditions typical of nearby disk galaxies. We employ the techniques developed in Armillotta+21 to post-process three…

Astrophysics of Galaxies · Physics 2022-05-04 Lucia Armillotta , Eve C. Ostriker , Yan-Fei Jiang

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

Cosmic rays (CRs) are thought to play an important role in galaxy evolution. We study their effect when coupled to other important sources of feedback, namely supernovae and stellar radiation, by including CR anisotropic diffusion and…

Astrophysics of Galaxies · Physics 2022-05-27 Marion Farcy , Joakim Rosdahl , Yohan Dubois , Jérémy Blaizot , Sergio Martin-Alvarez

The interaction between the strong winds in stellar colliding-wind binary (CWB) systems produces two shock fronts, delimiting the wind collision region (WCR). There, particles are expected to be accelerated mainly via diffusive shock…

High Energy Astrophysical Phenomena · Physics 2019-01-30 Emanuele Grimaldo , Anita Reimer , Ralf Kissmann , Felix Niederwanger , Klaus Reitberger

We investigate the effects of cosmic ray (CR) dynamics on cold, dense clouds embedded in a hot, tenuous galactic halo. If the magnetic field does not increase too much inside the cloud, the local reduction in Alfv\'en speed imposes a…

High Energy Astrophysical Phenomena · Physics 2017-01-25 Joshua Wiener , S. Peng Oh , Ellen G. Zweibel

Cosmic rays are energetic nuclei that permeate the entire Galactic disk. Their existence requires the presence of powerful particle accelerators. While Galactic supernova explosions may supply the required energy, there is growing evidence…

High Energy Astrophysical Phenomena · Physics 2024-07-11 Giada Peron , Sabrina Casanova , Stefano Gabici , Vardan Baghmanyan , Felix Aharonian

The X-ray emission from a simulated massive stellar cluster is investigated. The emission is calculated from a 3D hydrodynamical model which incorporates the mechanical feedback from the stellar winds of 3 O-stars embedded in a giant…

Solar and Stellar Astrophysics · Physics 2015-06-19 H. Rogers , J. M. Pittard

Observations of the $\gamma$-ray emission around star clusters, isolated supernova remnants, and pulsar wind nebulae indicate that the cosmic-ray (CR) diffusion coefficient near acceleration sites can be suppressed by a large factor…

Astrophysics of Galaxies · Physics 2021-04-07 Vadim A. Semenov , Andrey V. Kravtsov , Damiano Caprioli

Massive Star Clusters (SCs) have been proposed as additional contributors to Galactic Cosmic rays (CRs), to overcome the limitations of supernova remnants (SNRs) to reach the highest energy end of the CR spectrum. Thanks to fast mass losses…

High Energy Astrophysical Phenomena · Physics 2025-11-17 Giada Peron

Cosmic rays (CRs) are an important energy source in the circum-galactic medium (CGM) that impact the multi-phase gas structure and dynamics. We perform two-dimensional CR-magnetohydrodynamic simulations to investigate the role of CRs in…

Astrophysics of Galaxies · Physics 2022-06-14 Xiaoshan Huang , Yan-fei Jiang , Shane W. Davis

Cosmic rays (CRs) are thought to play a dynamically important role in several key aspects of galaxy evolution, including the structure of the interstellar medium, the formation of galactic winds, and the non-thermal pressure support of…

Astrophysics of Galaxies · Physics 2019-11-19 Yohan Dubois , Benoît Commerçon , Alexandre Marcowith , Loann Brahimi

Cosmic rays (CR) propagate through the galactic scales down to the smaller scales at which stars form. CRs are close to energy equipartition with the other components of the interstellar medium and can provide a support against gravity if…

Astrophysics of Galaxies · Physics 2019-02-13 Benoît Commerçon , Alexandre Marcowith , Yohan Dubois

Context: The environments of young star clusters are shaped by the interactions of the powerful winds of massive stars, and their feedback on the cluster birth cloud. Several such clusters show diffuse gamma-ray emission on the degree…

High Energy Astrophysical Phenomena · Physics 2025-05-28 Lucia Härer , Thibault Vieu , Brian Reville

We examine diffusive shock acceleration (DSA) of the pre-exisiting as well as freshly injected populations of nonthermal, cosmic-ray (CR) particles at weak cosmological shocks. Assuming simple models for thermal leakage injection and…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Hyesung Kang , Dongsu Ryu

Cosmological hydrodynamic simulations of large scale structure in the universe have shown that accretion shocks and merger shocks form due to flow motions associated with the gravitational collapse of nonlinear structures. Estimated speed…

Astrophysics · Physics 2015-06-24 Hyesung Kang , T. W. Jones

The observed bimodality in radio luminosity in galaxy clusters is puzzling. We investigate the possibility that cosmic-ray (CR) streaming in the intra-cluster medium can 'switch off' hadronically induced radio and gamma-ray emission. For…

High Energy Astrophysical Phenomena · Physics 2015-06-15 Joshua Wiener , S Peng Oh , Fulai Guo

In the Milky Way, cosmic rays (CRs) are dynamically important in the interstellar medium, contribute to hydrostatic balance, and may help regulate star formation. However, we know far less about the importance of CRs in galaxies whose gas…

Astrophysics of Galaxies · Physics 2021-01-27 Roland M. Crocker , Mark R. Krumholz , Todd A. Thompson

Cosmic ray (CR) sources leave signatures in the isotopic abundances of CRs. Current models of Galactic CRs that consider supernovae (SNe) shocks as the main sites of particle acceleration cannot satisfactorily explain the higher ${\rm…

High Energy Astrophysical Phenomena · Physics 2020-02-12 Siddhartha Gupta , Biman B. Nath , Prateek Sharma , David Eichler

We present a hydrodynamical simulation of the turbulent, magnetized, supernova (SN)-driven interstellar medium (ISM) in a stratified box that dynamically couples the injection and evolution of cosmic rays (CRs) and a self-consistent…

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