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Related papers: Cosmic-ray heating of molecular cloud cores

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The interaction of cosmic rays (CRs) with magnetic fields and the interstelar medium (ISM) leads to the production of nonthermal radiation. Although this has been a topic of study for many years, it still poses many challenges to the…

Comparison of appropriate theoretical derived line ratios with observational data can yield estimates of a plasma's physical parameters, such as electron density or temperature. The usual practice in the calculation of the line ratio is the…

Solar and Stellar Astrophysics · Physics 2014-11-20 J. G. Doyle , S. Chapman , P. Bryans , D. Perez-Suarez , A. Singh , H. Summers , D. W. Savin

The hot interstellar medium traces the stellar feedback and its role in regulating the eco-system of the Galaxy. I review recent progress in understanding the medium, based largely on X-ray absorption line spectroscopy, complemented by…

Astrophysics of Galaxies · Physics 2009-08-12 Q. Daniel Wang

Constraining the temperature and density structure of dense molecular cloud cores is fundamental for understanding the initial conditions of star formation. We use Herschel observations of the thermal FIR dust emission from nearby isolated…

Low-energy (~MeV) cosmic rays (CRs) ionize molecular clouds and create the neutral iron line (Fe I K\alpha) at 6.4 keV. On the other hand, high-energy (>~ GeV) CRs interact with the dense cloud gas and produce gamma rays. Based on a…

High Energy Astrophysical Phenomena · Physics 2021-02-22 Yutaka Fujita , Kumiko K. Nobukawa , Hidetoshi Sano

The Central Molecular Zone (CMZ) at the center of our Galaxy is the best template to study star formation processes under extreme conditions, similar to those in high-redshift galaxies. We observed on-the-fly maps of para-H$_{2}$CO…

Astrophysics of Galaxies · Physics 2016-11-09 K. Immer , J. Kauffmann , T. Pillai , A. Ginsburg , K. M. Menten

Following an approach initially outlined by McKee & Holliman, we investigate the structure and stability of dense, starless molecular cloud cores. We model those as spherical clouds in hydrostatic equilibrium and supported against gravity…

Astrophysics · Physics 2007-05-23 J. Kauffmann , F. Bertoldi

Absorption lines from the molecules OH+, H2O+, and H3+ have been observed in a diffuse molecular cloud along a line of sight near W51 IRS2. We present the first chemical analysis that combines the information provided by all three of these…

Astrophysics of Galaxies · Physics 2015-06-11 Nick Indriolo , D. A. Neufeld , M. Gerin , T. R. Geballe , J. H. Black , K. M. Menten , J. R. Goicoechea

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

Ionized interstellar gas is an important component of the interstellar medium and its lifecycle. The recent evidence for a widely distributed highly ionized warm interstellar gas with a density intermediate between the warm ionized medium…

Astrophysics of Galaxies · Physics 2021-07-14 W. D. Langer , J. L. Pineda , P. F. Goldsmith , E. T. Chambers , D. Riquelme , L. D. Anderson , M. Luisi , M. Justen , C. Buchbender

We present results of our study on eight dense cores, previously classified as starless, using infrared (3-160 {\micron}) imaging observations with \textit{AKARI} telescope and molecular line (HCN and N$_2$H$^+$) mapping observations with…

Astrophysics of Galaxies · Physics 2016-06-22 Gwanjeong Kim , Chang Won Lee , Maheswar Gopinathan , Woong-Seob Jeong , Mi-Ryang Kim

The bulk propagation speed of GeV-energy cosmic rays is limited by frequent scattering off hydromagnetic waves. Most galaxy evolution simulations that account for this confinement assume the gas is fully ionized and cosmic rays are…

High Energy Astrophysical Phenomena · Physics 2021-06-09 Chad Bustard , Ellen G. Zweibel

We demonstrate that ionization of $\text{H}_2$ by dark matter in dense molecular clouds can provide strong constraints on the scattering strength of dark matter with electrons. Molecular clouds have high UV-optical attenuation, shielding…

High Energy Physics - Phenomenology · Physics 2023-08-28 Anirudh Prabhu , Carlos Blanco

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 interstellar molecular clouds are the site of star formation and also the target for the cosmic ray protons to produce \gamma-rays via the hadronic process. The interstellar atomic gas is enveloping the molecular clouds and may also be…

Astrophysics of Galaxies · Physics 2015-06-15 Yasuo Fukui

Warm cores (or hot corinos) around low-mass protostellar objects show a rich chemistry with strong spatial variations. This chemistry is generally attributed to the sublimation of icy mantles on dust grains initiated by the warming effect…

Solar and Stellar Astrophysics · Physics 2015-05-19 Zainab Awad , Serena Viti , Mark P. Collings , David A. Williams

Five regions of massive star formation have been observed in various molecular lines in the frequency range $\sim 85-89$ GHz. The studied regions possess dense cores, which host young stellar objects. The physical parameters of the cores…

Astrophysics of Galaxies · Physics 2016-10-19 L. E. Pirogov , V. M. Shul'ga , I. I. Zinchenko , P. M. Zemlyanukha , O. N. Patoka , M. Thomasson

We will here discuss how the gamma-ray emission from molecular clouds can be used to probe the cosmic ray flux in distant regions of the Galaxy and to constrain the highly unknown cosmic ray diffusion coefficient. In particular we will…

We present three-dimensional astrochemical simulations and synthetic observations of magnetised, turbulent, self-gravitating molecular clouds. We explore various galactic interstellar medium environments, including cosmic-ray ionization…

Astrophysics of Galaxies · Physics 2021-01-20 Thomas G. Bisbas , Jonathan C. Tan , Kei E. I. Tanaka

The detection of complex organic molecules (COMs) toward cold sources such as pre-stellar cores (with T<10 K), has challenged our understanding of the formation processes of COMs in the interstellar medium. Recent modelling on COM chemistry…

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