Hydrodynamical simulations of the decay of high-speed molecular turbulence - I. Dense molecular regions

Pavlovski, G. and Smith, M.D. and Mac Low, M.-M. and Rosen, A. (2002) Hydrodynamical simulations of the decay of high-speed molecular turbulence - I. Dense molecular regions. Monthly Notices of the Royal Astronomical Society, 337 (2). pp. 477-487. ISSN 0035-8711. (doi:https://doi.org/10.1046/j.1365-8711.2002.05927.x) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

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Official URL
http://dx.doi.org/10.1046/j.1365-8711.2002.05927.x

Abstract

We present the results from three-dimensional hydrodynamical simulations of decaying high-speed turbulence in dense molecular clouds. We compare our results, which include a detailed cooling function, molecular hydrogen chemistry and a limited C and O chemistry, with those previously obtained for decaying isothermal turbulence. After an initial phase of shock formation, power-law decay regimes are uncovered, as in the isothermal case. We find that the turbulence decays faster than in the isothermal case because the average Mach number remains higher, owing to the radiative cooling. The total thermal energy, initially raised by the introduction of turbulence, decays only a little more slowly than the kinetic energy. We discover that molecule reformation, as the fast turbulence decays, is several times faster than that predicted for a non-turbulent medium. This is caused by moderate speed shocks which sweep through a large fraction of the volume, compressing the gas and dust. Through reformation, the molecular density and molecular column appear as complex patterns of filaments, clumps and some diffuse structure. In contrast, the molecular fraction has a wider distribution of highly distorted clumps and copious diffuse structure, so that density and molecular density are almost identically distributed during the reformation phase. We conclude that molecules form in swept-up clumps but effectively mix throughout via subsequent expansions and compressions.

Item Type: Article
Uncontrolled keywords: Hydrodynamics, ISM: clouds, ISM: kinematics and dynamics, Molecular processes, Shock waves, Turbulence
Subjects: Q Science > QB Astronomy > QB460 Astrophysics
Divisions: Faculties > Sciences > School of Physical Sciences > Centre for Astrophysics and Planetary Sciences
Depositing User: Giles Tarver
Date Deposited: 11 Aug 2015 10:03 UTC
Last Modified: 12 Aug 2015 14:22 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/50130 (The current URI for this page, for reference purposes)
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