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Related papers: Cosmic-ray ionisation in collapsing clouds

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We study penetration of interstellar cosmic rays (CRs) into molecular clouds surrounded by nonuniform diffuse envelopes. The present work generalizes our earlier model of CR self-modulation (Ivlev et al. 2018, Dogiel et al. 2018), in which…

High Energy Astrophysical Phenomena · Physics 2024-07-08 D. O. Chernyshov , A. V. Ivlev , A. M. Kiselev

Stars and more particularly massive stars, have a drastic impact on galaxy evolution. Yet the conditions in which they form and collapse are still not fully understood. In particular, the influence of the magnetic field on the collapse of…

Astrophysics of Galaxies · Physics 2015-05-27 P. Hennebelle , B. Commercon , M. Joos , R. S. Klessen , M. Krumholz , J. C. Tan , R. Teyssier

We investigate protostellar collapse of molecular cloud cores by numerical simulations, taking into account turbulence and magnetic fields. By using the adaptive mesh refinement technique, the collapse is followed over a wide dynamic range…

Solar and Stellar Astrophysics · Physics 2015-05-19 Tomoaki Matsumoto , Tomoyuki Hanawa

We explore the impact of cosmic rays (CRs) on cosmological adaptive-mesh refinement simulations of a forming 10^12 Msolar halo, focusing on the circumgalactic medium (CGM), and its resulting low-redshift structure and composition. In…

Astrophysics of Galaxies · Physics 2015-12-23 Munier Salem , Greg L. Bryan , Lauren Corlies

We examine the effect of magnetic fields on star cluster formation by performing simulations following the self-gravitating collapse of a turbulent molecular cloud to form stars in ideal MHD. The collapse of the cloud is computed for global…

Astrophysics · Physics 2009-11-13 Daniel Price , Matthew Bate

We present a suite of high-resolution cosmological simulations, using the FIRE-2 feedback physics together with explicit treatment of magnetic fields, anisotropic conduction and viscosity, and cosmic rays (CRs) injected by supernovae…

It is established that both radiative transfer and magnetic field have a strong impact on the collapse and the fragmentation of prestellar dense cores, but no consistent calculation exists yet at such scales. We present original AMR…

Solar and Stellar Astrophysics · Physics 2015-05-14 B. Commercon , P. Hennebelle , E. Audit , G. Chabrier , R. Teyssier

We studied the collapse of rotating molecular cloud cores with inclined magnetic fields, based on three-dimensional numerical simulations.The numerical simulations start from a rotating Bonnor-Ebert isothermal cloud in a uniform magnetic…

Astrophysics · Physics 2009-11-11 Masahiro N. Machida , Tomoaki Matsumoto , Tomoyuki Hanawa , Kohji Tomisaka

Non-thermal desorption of ices on interstellar grains is required to explain observations of molecules that are not synthesized efficiently in the gas phase in cold dense clouds. Perhaps the most important non-thermal desorption mechanism…

Astrophysics of Galaxies · Physics 2021-12-08 O. Sipilä , K. Silsbee , P. Caselli

Abridged. It is important for the star formation process to understand the collapse of a prestellar dense core. We investigate the effect of the magnetic field during the first collapse up to the formation of the firstcore, focusing…

Astrophysics · Physics 2009-11-13 P. Hennebelle , S. Fromang

Cosmological shock waves during structure formation not only play a decisive role for the thermalization of gas in virializing structures but also for the acceleration of relativistic cosmic rays (CRs) through diffusive shock acceleration.…

Astrophysics · Physics 2015-06-24 Christoph Pfrommer , Volker Springel , Torsten A. Ensslin , Martin Jubelgas

We reported the gamma-ray observation towards the giant molecular cloud Polaris Flare. Together with the dust column density map, we derived the cosmic ray density and spectrum in this cloud. Compared with the CR measured locally, the CR…

High Energy Astrophysical Phenomena · Physics 2021-12-08 Zhi-wei Cui , Rui-zhi Yang , Bing Liu

We study the effects of cosmic rays (CRs) on outflows from star-forming galaxies in the circum and inter-galactic medium (CGM/IGM), in high-resolution, fully-cosmological FIRE-2 simulations (accounting for mechanical and radiative stellar…

The Central Molecular Zone (CMZ), located in the centre of the Milky Way, is a roughly cylindrical structure of molecular gas extending up to parsecs around the supermassive black hole Sagittarius A*. The average H2 ionisation rate in the…

High Energy Astrophysical Phenomena · Physics 2025-08-05 Sruthiranjani Ravikularaman , Sarah Recchia , Vo Hong Minh Phan , Stefano Gabici

The evolution of radiation emitted during the dynamical collapse of metal-free protostellar clouds is investigated within a spherically symmetric hydrodynamical scheme that includes the transfer of radiation and the chemistry of the…

Astrophysics · Physics 2009-11-06 Emanuele Ripamonti , Francesco Haardt , Andrea Ferrara , Monica Colpi

The chemical complexity in low-metallicity hot cores has been confirmed by observations. We investigate the effect of varying physical parameters, such as temperature, density and the cosmic ray ionisation rate (CRIR), on the molecular…

Astrophysics of Galaxies · Physics 2024-07-10 Yara Sobhy , Hideko Nomura , Tetsuo Yamamoto , Osama Shalabeia

Cosmic rays are appealing as a source of ionization in starburst galaxies because of the great columns they can penetrate, but in the densest regions of starbursts, they may be stopped by pion production and ionization energy losses. I…

High Energy Astrophysical Phenomena · Physics 2012-04-13 Brian C. Lacki

Understanding how cosmic rays (CRs) propagate within the giant molecular clouds (GMCs) is critical for studying the dynamics and chemical processes inside the clouds. The flux of low-energy CRs inside the dense cores of GMCs strongly…

High Energy Astrophysical Phenomena · Physics 2024-12-03 Zhaodong Shi , Bing Liu , Rui-zhi Yang

Brown dwarfs and giant gas extrasolar planets have cold atmospheres with a rich chemical compositions from which mineral cloud particles form. Their properties, like particle sizes and material composition, vary with height, and the mineral…

Earth and Planetary Astrophysics · Physics 2016-06-22 Ch. Helling , P. B. Rimmer , I. M. Rodriguez-Barrera , Kenneth Wood , G. B. Robertson , C. R. Stark

We discuss evolution of the magnetic flux density and angular velocity in a molecular cloud core, on the basis of three-dimensional numerical simulations, in which a rotating magnetized cloud fragments and collapses to form a very dense…

Astrophysics · Physics 2009-11-13 Masahiro N Machida , Tomoaki Matsumoto , Kohji Tomisaka , Tomoyuki Hanawa