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Related papers: Cosmic-ray acceleration in young protostars

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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

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

Our Galaxy is the largest nuclear interaction experiment which we know, because of the interaction between cosmic ray particles and the interstellar material. Cosmic rays are particles, which have been accelerated in the Galaxy or in…

Astrophysics · Physics 2011-04-15 Peter L. Biermann

We assess the ionising effect of low energy protostellar cosmic rays in protoplanetary disks around a young solar mass star for a wide range of disk parameters. We assume a source of low energy cosmic rays located close to the young star…

Solar and Stellar Astrophysics · Physics 2020-01-08 D. Rodgers-Lee , A. M. Taylor , T. P. Downes , T. P. Ray

We consider the diffusive shock acceleration in interstellar bubbles created by powerful stellar winds of supernova progenitors. Under the moderate stellar wind magnetization the bubbles are filled by the strongly magnetized low density…

High Energy Astrophysical Phenomena · Physics 2018-02-14 V. N. Zirakashvili , V. S. Ptuskin

Low-energy cosmic rays, in particular protons with energies below 1 GeV, are significant drivers of the thermochemistry of molecular clouds. However, these cosmic rays are also greatly impacted by energy losses and magnetic field transport…

High Energy Astrophysical Phenomena · Physics 2021-09-08 Brandt A. L. Gaches , Stefanie Walch , Alex Lazarian

As long as magnetic fields remain frozen into the gas, the magnetic braking prevents the formation of protostellar discs. This condition is subordinate to the ionisation fraction characterising the inmost parts of a collapsing cloud. The…

Solar and Stellar Astrophysics · Physics 2015-03-25 Marco Padovani , Daniele Galli , Patrick Hennebelle , Benoît Commercon , Marc Joos

The formation of protostellar discs is severely hampered by magnetic braking, as long as magnetic fields remain frozen in the gas. The latter condition depends on the levels of ionisation that characterise the innermost regions of a…

Astrophysics of Galaxies · Physics 2015-06-22 Marco Padovani , Daniele Galli , Patrick Hennebelle , Benoît Commerçon , Marc Joos

Low-energy cosmic rays are a fundamental source of ionization for molecular clouds, influencing their chemical, thermal and dynamical evolution. The purpose of this work is to explore the possibility that a low-energy component of…

Solar and Stellar Astrophysics · Physics 2015-05-13 Marco Padovani , Daniele Galli , Alfred E. Glassgold

In this paper, we study the diffusive shock acceleration of cosmic-ray protons and nuclei, taking into account all the relevant interaction processes with photon backgrounds. We investigate how the competition between protons and nuclei is…

High Energy Astrophysical Phenomena · Physics 2015-05-13 D. Allard , R. J. Protheroe

Astrospheres and wind bubbles of massive stars are believed to be sources of cosmic rays with energies $E\lesssim 1\,$TeV. These particles are not directly detectable, but their impact on surrounding matter, in particular ionisation of…

High Energy Astrophysical Phenomena · Physics 2016-08-11 Florian Schuppan , Christian Röken , Natalie Fedrau , Julia Becker Tjus

Molecular clouds interacting with supernova remnants may be subject to a greatly enhanced irradiation by cosmic rays produced at the shocked interface between the ejecta and the molecular gas. Over the past decade, broad-band observations…

Astrophysics · Physics 2009-11-11 M. Fatuzzo , F. C. Adams , F. Melia

Although the origin of cosmic rays (CRs) remains an open question, collisionless magnetized shock waves are widely regarded as key sites for particle acceleration. Recent theories further suggest that shock-shock collisions in stellar…

Observations of large-scale radio emissions prove the existence of shock accelerated cosmic-ray electrons in galaxy clusters, while the lack of detected $\gamma$-rays limits the acceleration of cosmic-ray protons in galaxy clusters. This…

High Energy Astrophysical Phenomena · Physics 2020-04-22 Denis Wittor , Franco Vazza , Dongsu Ryu , Hyesung Kang

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

The formation of massive stars play a crucial role in galaxies from numerous points of view. The protostar generates a strong ultraviolet radiation field that ionizes its surroundings, and it drives powerful shock waves in the neighbouring…

High Energy Astrophysical Phenomena · Physics 2015-03-24 A. Gusdorf , A. Marcowith , M. Gerin , R. Guesten

We briefly discuss models of energetic particle acceleration by supernova shock in active starforming regions at different stages of their evolution. Strong shocks may strongly amplify magnetic fields due to cosmic ray driven instabilities.…

High Energy Astrophysical Phenomena · Physics 2012-02-21 A. M. Bykov , P. E. Gladilin , S. M. Osipov

We show that the secondary electrons ejected from the ionization of heavy ions can be injected into the acceleration process that occurs at supernova remnant shocks. This electron injection mechanism works since ions are ionized during the…

High Energy Astrophysical Phenomena · Physics 2009-11-06 G. Morlino

We present astrochemical photo-dissociation region models in which cosmic ray attenuation has been fully coupled to the chemical evolution of the gas. We model the astrochemical impact of cosmic rays, including those accelerated by…

Astrophysics of Galaxies · Physics 2019-06-26 Brandt A. L. Gaches , Stella S. R. Offner , Thomas G. Bisbas

Recent studies have suggested that low-energy cosmic rays (CRs) may be accelerated inside molecular clouds by the shocks associated with star formation. We use a Monte Carlo transport code to model the propagation of CRs accelerated by…

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