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

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Within a few parsecs around the central Black Hole Sgr A*, chemistry in the dense molecular cloud material of the circumnuclear disk (CND) can be affected by many energetic phenomena such as high UV-flux from the massive central star…

Cosmic rays are an essential ingredient in the evolution of the interstellar medium, as they dominate the ionisation of the dense molecular gas, where stars and planets form. However, since they are efficiently scattered by the galactic…

Astrophysics of Galaxies · Physics 2014-09-05 Solenn Vaupré , Pierre Hily-Blant , Cecilia Ceccarelli , Guillaume Dubus , Stefano Gabici , Thierry Montmerle

Near ultraviolet observations of OH+ and OH in diffuse molecular clouds reveal a preference for different environments. The dominant absorption feature in OH+ arises from a main component seen in CH+ (that with the highest CH+/CH column…

Astrophysics of Galaxies · Physics 2015-06-18 A. J. Porras , S. R. Federman , D. E. Welty , A. M. Ritchey

We present maps of a large number of dense molecular gas tracers across the Central Molecular Zone of our Galaxy. The data were taken with the CSIRO/CASS Mopra telescope in Large Projects in the 1.3cm, 7mm, and 3mm wavelength regimes. Here,…

Astrophysics of Galaxies · Physics 2015-06-18 Juergen Ott , Michael Burton , Paul Jones , David S. Meier

We report the first study of OH(1720 MHz) masers in the LMC in order to probe regions where supernova remnants interact with adjacent molecular clouds. Using the ATCA, we observed four sources in the LMC and detected a single OH(1720 MHz)…

Astrophysics · Physics 2007-05-23 D. A. Roberts , F. Yusef-Zadeh

The formation mechanism of the jet-aligned CO clouds found by NANTEN CO observations is studied by magnetohydrodynamical (MHD) simulations taking into account the cooling of the interstellar medium. Motivated by the association of the CO…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Y. Asahina , T. Ogawa , T. Kawashima , N. Furukawa , R. Enokiya , H. Yamamoto , Y. Fukui , R. Matsumoto

Outflows generated by protostars heavily affect the kinematics and chemistry of the hosting molecular cloud through strong shocks that enhance the abundance of some molecules. L1157 is the prototype of chemically active outflows, and a…

Theoretical and observational investigations have indicated that the abundance of carbon monoxide (CO) is very sensitive to intrinsic properties of the gaseous medium, such as density, metallicity, and the background UV field. In order to…

Astrophysics of Galaxies · Physics 2015-05-20 Rahul Shetty , Simon C. Glover , Cornelis P. Dullemond , Ralf S. Klessen

Aims: Our aims are threefold: a) To compare the $uv$ and mm-wave results; b) to interpret 13CO and 12CO abundances in terms of the physical processes which separately and jointly determine them; c) to interpret observed J=1-0 rotational…

Astrophysics · Physics 2009-11-13 H. S. Liszt

We present a model in which the 22 GHz H$_2$O masers observed in star-forming regions occur behind shocks propagating in dense regions (preshock density $n_0 \sim 10^6 - 10^8$ cm$^{-3}$). We focus on high-velocity ($v_s > 30$ km s$^{-1}$)…

Astrophysics of Galaxies · Physics 2015-06-16 David Hollenbach , Moshe Elitzur , Christopher F. McKee

The gas at the surfaces of molecular clouds in galaxies is heated and dissociated by photons from young stars both near and far. HI resulting from the dissociation of molecular hydrogen H2 emits hyperfine line emission at 21 cm, and warmed…

Astrophysics · Physics 2009-11-10 Ronald J. Allen , Harold I. Heaton , Michael J. Kaufman

In this paper we present high-resolution hydrodynamical models of warm ionized clouds embedded in a superwind, and compare the OVI and soft X-ray properties to the existing observational data. These models include thermal conduction, which…

Astrophysics · Physics 2009-11-13 A. Marcolini , D. K. Strickland , A. D'Ercole , T. M. Heckman , C. G. Hoopes

We have used archival far-ultraviolet spectra from observations made by HST/STIS and FUSE to determine the column densities and rotational excitation temperatures for CO and H2, respectively, along the lines of sight to 23 Galactic O and B…

Astrophysics · Physics 2009-01-19 Eric B. Burgh , Kevin France , Stephan R. McCandliss

This paper presents a detailed study of the chemistry in the outflow associated with the low-mass protostar NGC1333-IRAS2A down to 3" (650 AU) scales. Millimeter-wavelength aperture-synthesis observations from the OVRO and BIMA…

We present near-infrared and millimetre-line observations of the Tornado nebula (G357.7-0.1). We detected 2.12 micron_m H2 1-0 S(1) line emission towards the suspected site of interaction with a molecular cloud revealed by the presence of…

Astrophysics · Physics 2009-11-10 J. S. Lazendic , M. Wardle , M. G. Burton , F. Yusef-Zadeh , A. J. Green , J. B. Whiteoak

OH is a key molecule in H2O chemistry, a valuable tool for probing physical conditions, and an important contributor to the cooling of shock regions. OH participates in the re-distribution of energy from the protostar towards the…

Using the Short-Wavelength-Spectrometer on the Infrared Space Observatory (ISO), we obtained near- and mid-infrared spectra toward the brightest H_2 emission peak of the Orion OMC-1 outflow. A wealth of emission and absorption features were…

Astrophysics · Physics 2007-05-23 Dirk Rosenthal , Frank Bertoldi , Siegfried Drapatz

The role of feedback from massive stars is believed to be a key element in the evolution of molecular clouds. We use high-resolution 3D SPH simulations to explore the dynamical effects of a single O7 star located at the centre of a…

Astrophysics of Galaxies · Physics 2015-06-05 S. Walch , A. P. Whitworth , T. Bisbas , R. Wunsch , D. Hubber

OH masers at 1720 MHz have proven to be excellent indicators of interactions between supernova remnants and molecular clouds. OH excitation calculations suggest that the 6049 MHz OH maser line is excited for higher column densities than for…

Astrophysics · Physics 2008-10-28 Korinne E. McDonnell , Mark Wardle , Alan E. Vaughan

The collisional pumping of H$_2$O and CH$_3$OH masers in magnetohydrodynamic nondissociative C-type shocks is considered. A grid of C-type shock models with speeds in the range $5-70$ km s$^{-1}$ and preshock gas densities $n_{\rm H_2,0} =…

Astrophysics of Galaxies · Physics 2022-08-02 A. V. Nesterenok