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Related papers: Cosmic-ray ionisation in circumstellar discs

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Recent results from multi-wavelength observations of the inner few hundred pc of the Galactic center have added two new characteristics to the ISM in this unique region. One is the cosmic ray ionization rate derived from H$_3^+$…

Astrophysics of Galaxies · Physics 2019-12-25 F. Yusef-Zadeh , M. Wardle , I. Heywood , W. Cotton , M. Royster

The high ionization-state ions trace the hot gases in the universe, of which gaseous halos around galaxies are a major contributor. Following Qu & Bregman (2018), we calculate the gaseous halo contribution to the observed column density…

Astrophysics of Galaxies · Physics 2018-08-01 Zhijie Qu , Joel N. Bregman

We model the transport of cosmic ray nuclei in the Galaxy by means of a new numerical code. Differently from previous numerical models we account for a generic spatial distribution of the diffusion coefficient. We found that in the case of…

Astrophysics · Physics 2016-05-19 C. Evoli , D. Gaggero , D. Grasso , L. Maccione

To investigate the interstellar medium (ISM) and Galactic cosmic rays (CRs) in the solar neighborhood, we analyzed ${\gamma}$-ray data by Fermi Large Area Telescope (LAT) for five nearby molecular cloud regions. Our data includes the…

High Energy Astrophysical Phenomena · Physics 2025-06-23 Tsunefumi Mizuno , Katsuhiro Hayashi , Hinako Ochi , Igor V. Moskalenko , Elena Orlando , Andrew W. Strong

We report on the effects of cosmic rays (CRs) on the abundance of CO in $\rm H_2$ clouds under conditions typical for star-forming galaxies in the Universe. We discover that this most important molecule for tracing H$_2$ gas is very…

Astrophysics of Galaxies · Physics 2015-06-23 Thomas G. Bisbas , Padelis P. Papadopoulos , Serena Viti

We investigate the propagation of ultra-high energy cosmic ray nuclei (A = 1-56) from cosmologically distant sources through the cosmic radiation backgrounds. Various models for the injected composition and spectrum and of the cosmic…

Astrophysics · Physics 2014-10-13 Dan Hooper , Subir Sarkar , Andrew M. Taylor

Diffuse emission is produced in energetic cosmic ray (CR) interactions, mainly protons and electrons, with the interstellar gas and radiation field and contains the information about particle spectra in distant regions of the Galaxy. It may…

Astrophysics · Physics 2008-11-26 Igor V. Moskalenko , Andrew W. Strong , Seth W. Digel , Troy A. Porter

The role of cosmic rays generated by supernovae and young stars has very recently begun to receive significant attention in studies of galaxy formation and evolution due to the realization that cosmic rays can efficiently accelerate…

High Energy Astrophysical Phenomena · Physics 2018-04-11 R. Farber , M. Ruszkowski , H. -Y. K. Yang , E. G. Zweibel

Cosmic rays provide an important source for free electrons in the Earth's atmosphere and also in dense interstellar regions where they produce a prevailing background ionization. We utilize a Monte Carlo cosmic ray transport model for…

Solar and Stellar Astrophysics · Physics 2015-06-16 Paul Rimmer , Christiane Helling

Cosmic rays are the main agents in controlling the chemical evolution and setting the ambipolar diffusion time of a molecular cloud. We summarise the processes causing the energy degradation of cosmic rays due to their interaction with…

Astrophysics of Galaxies · Physics 2014-06-11 Marco Padovani , Patrick Hennebelle , Daniele Galli

We study the properties of cosmic-ray (CR) driven galactic winds from the warm interstellar medium using idealized spherically symmetric time-dependent simulations. The key ingredients in the model are radiative cooling and…

Astrophysics of Galaxies · Physics 2023-08-11 Shaunak Modak , Eliot Quataert , Yan-Fei Jiang , Todd A. Thompson

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 excess of continuum gamma-ray emission from the Galaxy above 1 GeV is an unsolved puzzle. It may indicate that the interstellar nucleon or electron spectra are harder than local direct measurements, as could be the case if a local…

Astrophysics · Physics 2011-05-23 I. V. Moskalenko , A. W. Strong , O. Reimer

Cosmic rays (CRs) are a pivotal non-thermal component of galaxy formation and evolution. However, the intricacies of CR physics, particularly how they propagate in the circumgalactic medium (CGM), remain largely unconstrained. In this work,…

Cosmic rays (CRs) are an integral part of the non-thermal pressure budget in the interstellar medium (ISM) and are the leading-order ionization mechanism in cold molecular clouds. We study the impacts that different microphysical CR…

Motivated by recent experimental proposals to search for extragalactic cosmic rays (including anti-matter from distant galaxies), we study particle propagation through the intergalactic medium (IGM). We first use estimates of the magnetic…

The ratio between secondary and primary cosmic ray particles is the main source of information about cosmic ray propagation in the Galaxy. Primary cosmic rays are thought to be accelerated mainly in Supernova Remnant (SNR) shocks and then…

High Energy Astrophysical Phenomena · Physics 2019-07-10 Virginia Bresci , Elena Amato , Pasquale Blasi , Giovanni Morlino

We investigate the effects of the nearby interstellar medium (ISM) on the locally measured cosmic-ray (CR) spectra. Using the GALPROP code we explore how variations in the local gas and source distributions affect spectral features at low…

High Energy Astrophysical Phenomena · Physics 2026-03-26 Troy A. Porter , Igor V. Moskalenko , Alan C. Cummings , Gudlaugur Johannesson

In a recent paper (Moskalenko et al., 2002), it has been shown that the flux of secondary cosmic ray (CR) antiprotons appears to be contradictory to measurements of secondary to primary nuclei ratios in cosmic rays when calculated in the…

Astrophysics · Physics 2010-05-27 V. S. Ptuskin , I. V. Moskalenko , F. C. Jones , A. W. Strong , S. G. Mashnik

Cosmic ray protons interacting with gas at the mean density of the interstellar medium in starburst galaxies lose energy rapidly via inelastic collisions with ambient nuclei. The resulting pions produce secondary electrons and positrons,…

Astrophysics · Physics 2008-11-26 Todd A. Thompson , Eliot Quataert , Eli Waxman