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Related papers: Cold Clouds as Cosmic-Ray Detectors

200 papers

Cosmic rays are an important source of heating in the interstellar medium, in particular in dense molecular cloud cores shielded from the external ultraviolet radiation field. The limits placed on the cosmic-ray ionization rate from…

Solar and Stellar Astrophysics · Physics 2015-02-12 Daniele Galli , Marco Padovani

Cosmic rays are a fundamental source of ionization for molecular and diffuse clouds, influencing their chemical, thermal, and dynamical evolution. The amount of cosmic rays inside a cloud also determines the $\gamma$-ray flux produced by…

High Energy Astrophysical Phenomena · Physics 2015-09-18 G. Morlino , S. Gabici , J. Krause

We consider the rate of ionization of diffuse and molecular clouds in the interstellar medium by Galactic cosmic rays (GCR) in order to constrain its low energy spectrum. We extrapolate the GCR spectrum obtained from PAMELA at high energies…

Astrophysics of Galaxies · Physics 2015-06-04 Biman B. Nath , Nayantara Gupta , Peter L. Biermann

Determining gas content and star formation rate has known remarkable progress in field galaxies, but has been much less investigated in galaxies inside clusters. We present the first CO observations of luminous infrared galaxies (LIRGs)…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 P. Jablonka , F. Combes , K. Rines , R. Finn , T. Welch

The chemistry of shielded molecular gas is primarily driven by energetic, charged particles dubbed cosmic rays (CRs), in particular those with energies under 1 GeV. CRs ionize molecular hydrogen and helium, the latter of which contributes…

Astrophysics of Galaxies · Physics 2026-04-01 Arghyadeb Roy , Brandt A. L. Gaches , Jonathan C. Tan

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 investigate a mechanism for accelerating cool (10$^4$ K) clouds in the circumgalactic medium (CGM) with cosmic rays (CRs), possibly explaining some characteristics of observed high velocity clouds (HVCs). Enforcing CRs to stream down…

Astrophysics of Galaxies · Physics 2019-07-31 Joshua Wiener , Ellen G. Zweibel , Mateusz Ruszkowski

We study non-thermal emissions from cool cores in galaxy clusters. We adopted a recent model, in which cosmic-rays (CRs) prevail in the cores and stably heat them through CR streaming. The non-thermal emissions come from the interaction…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Yutaka Fujita , Yutaka Ohira

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

Ions (e.g., H$_3^+$, H$_2$O$^+$) have been used extensively to quantify the cosmic-ray ionization rate (CRIR) in diffuse sightlines. However, measurements of CRIR in low-to-intermediate density gas environments are rare, especially when…

Astrophysics of Galaxies · Physics 2023-01-19 Gan Luo , Zhi-Yu Zhang , Thomas G. Bisbas , Di Li , Ningyu Tang , Junzhi Wang , Ping Zhou , Pei Zuo , Nannan Yue , Jing Zhou , Lingrui Lin

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

We present new calculations of the photoionization of interstellar matter within ~5 pc of the Sun (which we refer to as the Complex of Local Interstellar Clouds or CLIC) by directly observed radiation sources including nearby hot stars and…

Astrophysics · Physics 2009-11-06 Jonathan D. Slavin , Priscilla C. Frisch

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…

Low-energy cosmic rays (LECRs) contribute substantially to the energy balance of the interstellar medium. They play also significant role in the heating and chemistry of gas, and, consequently, on the star formation process. Because of the…

High Energy Astrophysical Phenomena · Physics 2021-02-24 Bing Liu , Rui-zhi Yang , Felix Aharonian

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 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…

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

Propagation of cosmic rays (CRs) from their sources to the observer is described mainly as plain diffusion at high energies, while at lower energies there are other physical processes involved, both in the interstellar space and in the…

High Energy Astrophysical Phenomena · Physics 2017-01-11 S. Della Torre , M. Gervasi , D. Grandi , G. Johannesson , G. La Vacca , N. Masi , I. V. Moskalenko , E. Orlando , T. A. Porter , L. Quadrani , P. G. Rancoita , D. Rozza

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…

It is expected that cosmic rays (CRs) escape from high-redshift galaxies at redshift $z\sim 10 \, - \, 20$ because CRs are accelerated by supernova remnants of the first stars. Although ultraviolet and X-ray photons are widely considered…

High Energy Astrophysical Phenomena · Physics 2023-06-07 Shota L. Yokoyama , Yutaka Ohira