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Related papers: The CH+ Abundance in Turbulent, Diffuse Molecular …

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We have designed a simple multi-scale method that identifies turbulent motions in hydrodynamical grid simulations. The method does not assmume ant a-priori coherence scale to distinguish laminar and turbulent flows. Instead, the local mean…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 F. Vazza , E. Roediger , M. Brueggen

We carry out direct numerical simulations of turbulent astrophysical media that explicitly track ionizations, recombinations, and species-by-species radiative cooling. The simulations assume solar composition and follows the evolution of…

Astrophysics of Galaxies · Physics 2015-06-23 William J Gray , Evan Scannapieco , Daniel Kasen

The z=0.89 molecular absorber toward PKS1830-211 provides us with the opportunity to probe the chemical and physical properties of the interstellar medium in the disk of a galaxy at a look-back time of half the present age of the Universe.…

This chapter reviews the nature of turbulence in the Galactic interstellar medium (ISM) and its connections to the star formation (SF) process. The ISM is turbulent, magnetized, self-gravitating, and is subject to heating and cooling…

Astrophysics of Galaxies · Physics 2017-03-15 Enrique Vazquez-Semadeni

We further characterize the structures tentatively identified on thermal and chemical grounds as the sites of dissipation of turbulence in molecular clouds (Papers I and II). Our study is based on two-point statistics of line centroid…

Astrophysics · Physics 2009-11-13 Pierre Hily-Blant , Edith Falgarone , Jerome Pety

Supersonic turbulence in molecular clouds is a dominant agent that strongly affects the clouds' evolution and star formation activity. Turbulence may be initiated and maintained by a number of processes, acting at a wide range of physical…

Astrophysics of Galaxies · Physics 2014-11-20 C. M. Brunt , M. H. Heyer , M. -M. Mac Low

In high-resolution X-ray observations of the hot plasma in clusters of galaxies significant structures caused by AGN feedback, mergers, and turbulence can be detected. Many clusters have been observed by Chandra in great depth and at high…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-13 F. Hofmann , J. S. Sanders , K. Nandra , N. Clerc , M. Gaspari

Nuclear burning plays a key role in a wide range of astrophysical stellar transients, including thermonuclear, pair instability, and core collapse supernovae, as well as kilonovae and collapsars. Turbulence is now understood to also play a…

Solar and Stellar Astrophysics · Physics 2020-02-07 Yossef Zenati , Robert T. Fisher

In our recent works we proposed a theory of turbulence in inertial gas flow via the mean field effect of an intermolecular potential. We found that, in inertial flow, turbulence indeed spontaneously develops from a laminar initial…

Fluid Dynamics · Physics 2022-12-14 Rafail V. Abramov

Using self-gravitational hydrodynamical numerical simulations, we investigated the evolution of high-density turbulent molecular clouds swept by a colliding flow. The interaction of shock waves due to turbulence produces networks of thin…

Solar and Stellar Astrophysics · Physics 2015-06-23 Tomoaki Matsumoto , Kazuhito Dobashi , Tomomi Shimoikura

The chemistry of the diffuse interstellar medium is driven by the combined influences of cosmic rays, ultraviolet (UV) radiation, and turbulence. Previously detected at the outer edges of photodissociation regions (PDRs) and formed from the…

Astrophysics of Galaxies · Physics 2021-04-14 Maryvonne Gerin , Harvey Liszt

The physical processes involved in diffusion of Galactic cosmic rays in the interstellar medium are addressed. We study the possibility that the nonlinear MHD cascade sets the power-law spectrum of turbulence which scatters charged…

Astrophysics · Physics 2008-11-26 V. S. Ptuskin , I. V. Moskalenko , F. C. Jones , A. W. Strong , V. N. Zirakashvili

Collisionless dissipation of macroscopic energy into heat is an unsolved problem of space and astrophysical plasmas, e.g., solar wind and Earth's magnetosheath. The most viable process under consideration is the turbulent-cascade of…

Plasma Physics · Physics 2021-10-04 Neeraj Jain , Jörg Büchner , Horia Comişel , Uwe Motschmann

The ISM is a turbulent, multi-phase, and multi-scale medium following scaling relations. Analytical models of galactic gaseous disks need to take into account the multi-scale and multi-phase nature of the interstellar medium. They can be…

Astrophysics of Galaxies · Physics 2022-07-27 T. Lizée , B. Vollmer , J. Braine , P. Gratier , F. Bigiel

We present models of turbulent mixing at the boundaries between hot (T~10^{6-7} K) and warm material (T~10^4 K) in the interstellar medium, using a three-dimensional magnetohydrodynamical code, with radiative cooling. The source of…

Astrophysics · Physics 2009-11-11 A. Esquivel , R. A. Benjamin , A. Lazarian , J. Cho , S. N. Leitner

We analyzed absorption features arising from interstellar neutral carbon that appeared in the UV spectra of 89 stars recorded in the highest resolution echelle modes of STIS on HST so that we could determine the relative populations of…

Astrophysics of Galaxies · Physics 2011-05-30 Edward B. Jenkins , Todd M. Tripp

An accurate treatment of the multiphase interstellar medium (ISM) in hydrodynamic galaxy simulations requires that we follow not only the thermal evolution of the gas, but also the evolution of its chemical state, including its molecular…

Astrophysics of Galaxies · Physics 2015-06-18 Alexander J. Richings , Joop Schaye , Benjamin D. Oppenheimer

In this study, we explore the impact of inhomogeneities in the spatial distribution of interstellar dust on spatial scales of $\le1$ au caused by ion shadowing forces on the optical properties of diffuse interstellar medium (ISM) as well as…

Astrophysics of Galaxies · Physics 2020-05-27 Andrei B. Ostrovskii , S. Yu. Parfenov , A. I. Vasyunin , A. V. Ivlev , V. A. Sokolova

In order to understand the origin of observed molecular cloud properties, it is critical to understand how clouds interact with their environments during their formation, growth, and collapse. It has been suggested that accretion-driven…

Astrophysics of Galaxies · Physics 2018-12-21 Juan C. Ibáñez-Mejía , Mordecai-Mark Mac Low , Ralf S. Klessen , Christian Baczynski

Diffuse interstellar clouds show large abundances of H_3^+ which can be maintained only by a high ionization rate of H_2. Cosmic rays are the dominant ionization mechanism in this environment, so the large ionization rate implies a high…

High Energy Astrophysical Phenomena · Physics 2011-02-11 Nick Indriolo , Brian D. Fields , Benjamin J. McCall