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Related papers: Enhanced OH in C-type shock waves in molecular clo…

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We report the detection and investigate the properties of high-excitation lambda-doubling line emission of hydroxyl (OH) detected towards three asymptotic giant branch (AGB) stars (W Hya, R Dor, and IK Tau) using ALMA. The OH lines are…

Solar and Stellar Astrophysics · Physics 2019-03-06 T. Khouri , L. Velilla-Prieto , E. De Beck , W. H. T. Vlemmings , H. Olofsson , B. Lankhaar , J. H. Black , A. Baudry

Chandra gratings spectra of a sample of 15 massive OB stars were analyzed under the basic assumption that the X-ray emission is produced in an ensemble of shocks formed in the winds driven by these objects. Shocks develop either as a result…

Astrophysics · Physics 2009-11-13 Svetozar A. Zhekov , Francesco Palla

We investigate the chemical evolution of a forming molecular cloud behind an interstellar shock wave. We conduct three-dimensional magnetohydrodynamics simulations of the converging flow of atomic gas, including a simple chemical network…

Astrophysics of Galaxies · Physics 2026-01-08 Yuto Komichi , Yuri Aikawa , Kazunari Iwasaki , Kenji Furuya

Motivated by recent observations with Herschel/PACS, and the availability of new rate coefficients for the collisional excitation of CO (Yang et al. 2010), the excitation of warm astrophysical CO is revisited with the use of numerical and…

Astrophysics of Galaxies · Physics 2015-06-04 David A. Neufeld

Water is an important molecule in interstellar and circumstellar environments. Previous observations of mid-infrared rotational lines of OH suggest that these lines may be used to probe the photodissociation of water. In this work, cross…

Astrophysics of Galaxies · Physics 2021-06-30 Benoît Tabone , Marc C. van Hemert , Ewine F. van Dishoeck , John H. Black

Supernova remnants (SNRs) exert strong influence on the physics and chemistry of the nearby molecular clouds (MCs) through shock waves and the cosmic rays (CRs) they accelerate. To investigate the SNR-cloud interaction in the prototype…

Astrophysics of Galaxies · Physics 2024-03-21 Tian-Yu Tu , Yang Chen , Ping Zhou , Samar Safi-Harb

We model the temperature and chemical structure of molecular clouds as a function of depth into the cloud, assuming a cloud of constant density n illuminated by an external FUV (6 eV < E < 13.6 eV) flux G_0 (scaling factor in multiples of…

Astrophysics · Physics 2011-02-11 David Hollenbach , Michael J. Kaufman , Edwin A. Bergin , Gary J. Melnick

The supernova explosion increases cosmic ray and x-ray fluxes in the surrounding interstellar medium. Cosmic ray particles and x-ray radiation penetrate nearby molecular clouds and affect the chemical and thermal evolution of the gas. Here…

Astrophysics of Galaxies · Physics 2019-12-25 A. V. Nesterenok

The hydroxyl radical (OH) is found in various environments within the interstellar medium (ISM) of the Milky Way and external galaxies, mostly either in diffuse interstellar clouds or in the warm, dense environments of newly formed low-mass…

Supernovae (SNe) inject $\sim 10^{51}$ erg in the interstellar medium, thereby shocking and heating the gas. A substantial fraction of this energy is later lost via radiative cooling. We present a post-processing module for the FLASH code…

High Energy Astrophysical Phenomena · Physics 2023-05-24 Ekaterina I. Makarenko , Stefanie Walch , Seamus D. Clarke , Daniel Seifried , Thorsten Naab , Pierre C. Nürnberger , Tim-Eric Rathjen

Aims: Our aim is to identify the dominant molecular cooling lines and characteristic emission features in the 1.3 mm window of distinct regions in the northern part of the Orion A molecular cloud. By defining and analysing template regions,…

Astrophysics of Galaxies · Physics 2020-04-15 N. Brinkmann , F. Wyrowski , J. Kauffmann , D. Colombo , K. M. Menten , X. D. Tang , R. Güsten

A collisionless shock may be strongly modified by the presence of neutral atoms through the processes of charge exchange between ions and neutrals and ionization of the latter. These two processes lead to exchange of energy and momentum…

High Energy Astrophysical Phenomena · Physics 2015-06-04 P. Blasi , G. Morlino , R. Bandiera , E. Amato , D. Caprioli

Deep optical CCD images of the supernova remnant G 15.1-1.6 were obtained and filamentary and diffuse emission has been discovered. The images, taken in the emission lines of Halpha+[N II], [S II] and [O III], reveal filamentary and diffuse…

{It has recently been proposed that giant molecular complexes form at the sites where streams of diffuse warm atomic gas collide at transonic velocities.} {We study the global statistics of molecular clouds formed by large scale colliding…

Astrophysics · Physics 2009-11-13 P. Hennebelle , R. Banerjee , E. Vazquez-Semadeni , R. Klessen , E. Audit

We present the first results on the diffuse transition clouds observed in [CII] line emission at 158 microns (1.9 THz) towards Galactic longitudes near 340deg (5 LOSs) and 20deg (11 LOSs) as part of the GOT C+ survey. Out of the total 146…

Astrophysics of Galaxies · Physics 2015-05-19 T. Velusamy , W. D. Langer , J. L. Pineda , P. F. Goldsmith , D. Li. , H. W. Yorke

Supernovae and their remnants provide energetic feedback to the ambient interstellar medium (ISM), which is often distributed in multiple gas phases. Among them, warm molecular hydrogen (H$_2$) often dominates the cooling of the shocked…

Astrophysics of Galaxies · Physics 2022-11-29 Yunwei Deng , Zhi-Yu Zhang , Ping Zhou , Junzhi Wang , Min Fang , Lingrui Lin , Fuyan Bian , Zhiwei Chen , Yong Shi , Guoyin Chen , Hui Li

The atomic-to-molecular hydrogen (H/H2) transition has been extensively studied as it controls the fraction of gas in a molecular state in an interstellar cloud. This fraction is linked to star-formation by the Schmidt-Kennicutt law. While…

Astrophysics of Galaxies · Physics 2021-12-08 Vincent Maillard , Emeric Bron , Franck Le Petit

Expansion of wind-blown bubbles or HII regions lead to formation of shocks in the interstellar medium, which compress surrounding gas into dense layers. We made spatially and velocity-resolved observations of the RCW~120 PDR and nearby…

Astrophysics of Galaxies · Physics 2023-01-18 M. S. Kirsanova , Ya. N. Pavlyuchenkov , A. O. H. Olofsson , D. A. Semenov , A. F. Punanova

We present the results of GBT observations of all four ground-state hydroxyl (OH) transitions toward 15 supernova remnants (SNRs) which show OH(1720 MHz) maser emission. This species of maser is well established as an excellent tracer of an…

Astrophysics · Physics 2009-11-13 J. W. Hewitt , F. Yusef-Zadeh , M. Wardle

The oxygen-bearing molecular ions OH+, H2O+, and H3O+ are key species that probe the ionization rate of (partially) molecular gas that is ionized by X-rays and cosmic rays permeating the interstellar medium. We report Herschel far-infrared…

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