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The turbulent environment of low-mass dense cores

Published online by Cambridge University Press:  01 August 2006

E. Falgarone ,
P. Hily-Blant ,
J. Pety  and
G. Pineau des Forêts
E. Falgarone
Affiliation:
LERMA/LRA, Ecole Normale Supérieure, 24 rue Lhomond, 75005 Paris, France email: [email protected]
P. Hily-Blant
Affiliation:
IRAM, 300 rue de la Piscine, 38406 Saint Martin d'Hères, France email: [email protected], [email protected]
J. Pety
Affiliation:
LERMA/LRA, Ecole Normale Supérieure, 24 rue Lhomond, 75005 Paris, France email: [email protected] IRAM, 300 rue de la Piscine, 38406 Saint Martin d'Hères, France email: [email protected], [email protected]
G. Pineau des Forêts
Affiliation:
LERMA/LRA, Ecole Normale Supérieure, 24 rue Lhomond, 75005 Paris, France email: [email protected] IAS, Université Paris-Sud, 91405 Orsay, France email: [email protected]
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Abstract

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The signatures of intermittent dissipation of turbulent energy have been sought in the translucent environment of a low-mass dense core. Molecular line observations reveal a network of narrow filamentary structures, found on statistical grounds to be the locus of the largest velocity shears. Three independent properties of these structures make them the plausible sites of intermittent dissipation of turbulence: (1) gas there is warmer and more diluted than average, (2) it bears the signatures of a non-equilibrium chemistry triggered by impulsive heating due to turbulence dissipation, and (3) the power that these structures radiate in the gas cooling lines (mostly H2) is so large that it balances the total energy injection rate of the turbulent cascade, for a volume filling factor of only a few percents, consistent with other observations in the Solar Neighborhood. These filamentary structures may act as tiny seeds of gas condensation in diffuse molecular gas. They do not exhibit the properties of steady-state low-velocity magneto-hydrodynamic (MHD) shocks, as presently modelled.

Keywords

TurbulenceastrochemistryMHDISM:evolutionISM:structureISM:moleculesISM:cloudstars:formationlines:profilesradio lines:ISM
Type
Contributed Papers
Information
Proceedings of the International Astronomical Union , Volume 2 , Symposium S237: Triggered Star Formation in a Turbulent ISM , August 2006 , pp. 24 - 30
Copyright
Copyright © International Astronomical Union 2007

References

Crane, P., Lambert, D.L., & Sheffer, Y. 1995, ApJS 99, 107CrossRefGoogle Scholar
Elmegreen, B.G., & Scalo, J. 2004, ARAA 42, 211CrossRefGoogle Scholar
Falgarone, E., Pineau, des Foréts G., Hily-Blant, P. & Schilke, P. 2006, A&A 452, 511Google Scholar
Falgarone, E., Verstraete, L., Pineau, des Foréts G. & Hily-Blant, P. 2005, A&A 433, 997Google Scholar
Falgarone, E., Pety, J. & Hily-Blant, P. in preparationGoogle Scholar
Flower, D., & Pineau des Foréts, G. 1998, MNRAS 297, 1182CrossRefGoogle Scholar
Frisch, U., Sulem, P.-L., & Nelkin, M. 1978, JFM 87, 719CrossRefGoogle Scholar
Gredel, R. 1997, A&A 320, 929Google Scholar
Gredel, R., Pineaudes Foréts, G. des Foréts, G. & Federman, S.R. 2002, A&A 389, 993Google Scholar
Gry, C., Boulanger, F., Nehmé, C. et al. 2002, A&A 391, 675Google Scholar
Heiles, C. 2000, AJ 119, 923CrossRefGoogle Scholar
Heithausen, A., Bertoldi, F., & Bensch, F. 2002, A&A 383, 591Google Scholar
Hily-Blant, P. 2004, PhD, Université Paris-SudGoogle Scholar
Hily-Blant, P., & Falgarone, E. 2006, A&A acceptedGoogle Scholar
Hily-Blant, P., Pety, J., & Falgarone, E. in preparationGoogle Scholar
Joulain, K., Falgarone, E., Pineau, des Foréts G., & Flower, D. 1998, A&A 340, 241Google Scholar
Kolmogorov, A.N. 1962, JFM 13, 82CrossRefGoogle Scholar
Lacour, S., Ziskin, V., Hébrard, G., et al. 2005, ApJ 627, 251CrossRefGoogle Scholar
Lambert, D.L., & Danks, A.C. 1986, ApJ 303, 401CrossRefGoogle Scholar
Landau, L.D., & Lifchitz, E.M. 1959, Fluid Mechanics, Addison-WesleyGoogle Scholar
Lesaffre, P., Gerin, M., & Hennebelle, P. 2006, A&A submittedGoogle Scholar
Lis, D., Pety, J., Phillips, T.G., & Falgarone, E. 1996, ApJ 463, 623CrossRefGoogle Scholar
Liszt, H.S., & Lucas, R. 1996, A&A 307, 237Google Scholar
Lucas, R., & Liszt, H.S. 2000, A&A 355, 333Google Scholar
MacLow, M.-M., & Klessen, R. 2004, Rev.Mod.Phys. 76, 125CrossRefGoogle Scholar
Moffatt, H.K., Kida, S., & Ohkitani, K. 1994, JFM 259, 241CrossRefGoogle Scholar
Neufeld, D.A., Kaufman, M.J., Goldsmith, P.F., et al. 2002, ApJ 580, 278CrossRefGoogle Scholar
Nguyen, T. K., Hartquist, T. W., & Williams, D. A. 2001, A&A 366, 662Google Scholar
Pety, J., & Falgarone, E. 2000, A&A 356, 279Google Scholar
Pety, J., & Falgarone, E. 2003, A&A 412, 417Google Scholar
Plume, R., Kaufman, M.J., Neufeld, D.A., et al. 2004, ApJ 605, 247CrossRefGoogle Scholar
Porter, D.H., Pouquet, A., & Woodward, P.R. 1993, Phys. Fluids 6, 2133CrossRefGoogle Scholar