Supernova driving. II. Compressive ratio in molecular-clou turbulence

The compressibility of molecular cloud (MC) turbulence plays a crucial role in star formation models, because it controls the amplitude and distribution of density fluctuations. The relation between the compressive ratio (the ratio of powers in compressive and solenoidal motions) and the statistics...

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Detalles Bibliográficos
Autores: Pan, Liubin, Padoan, Paolo, Haugbolle, Troels, Nordlund, Ake
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2016
País:España
Institución:Universidad de Barcelona
Repositorio:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/148762
Acceso en línea:https://hdl.handle.net/2445/148762
Access Level:acceso abierto
Palabra clave:Magnetohidrodinàmica
Turbulència
Formació d'estels
Magnetohydrodynamics
Turbulence
Star formation
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spelling Supernova driving. II. Compressive ratio in molecular-clou turbulencePan, LiubinPadoan, PaoloHaugbolle, TroelsNordlund, AkeMagnetohidrodinàmicaTurbulènciaFormació d'estelsMagnetohydrodynamicsTurbulenceStar formationThe compressibility of molecular cloud (MC) turbulence plays a crucial role in star formation models, because it controls the amplitude and distribution of density fluctuations. The relation between the compressive ratio (the ratio of powers in compressive and solenoidal motions) and the statistics of turbulence has been previously studied systematically only in idealized simulations with random external forces. In this work, we analyze a simulation of large-scale turbulence (250 pc) driven by supernova (SN) explosions that has been shown to yield realistic MC properties. We demonstrate that SN driving results in MC turbulence with a broad lognormal distribution of the compressive ratio, with a mean value approximate to 0.3, lower than the equilibrium value of approximate to 0.5 found in the inertial range of isothermal simulations with random solenoidal driving. We also find that the compressibility of the turbulence is not noticeably affected by gravity, nor are the mean cloud radial (expansion or contraction) and solid-body rotation velocities. Furthermore, the clouds follow a general relation between the rms density and the rms Mach number similar to that of supersonic isothermal turbulence, though with a large scatter, and their average gas density probability density function is described well by a lognormal distribution, with the addition of a high-density power-law tail when self-gravity is included.Institute of Physics (IOP)2016info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionapplication/pdfhttps://hdl.handle.net/2445/148762Articles publicats en revistes (Institut de Ciències del Cosmos (ICCUB))reponame:Dipòsit Digital de la UBinstname:Universidad de BarcelonaInglésReproducció del document publicat a: https://doi.org/10.3847/0004-637X/825/1/30Astrophysical Journal, 2016, vol. 825, num. 1, p. 30https://doi.org/10.3847/0004-637X/825/1/30(c) American Astronomical Society, 2016info:eu-repo/semantics/openAccessoai:diposit.ub.edu:2445/1487622026-05-27T06:46:51Z
dc.title.none.fl_str_mv Supernova driving. II. Compressive ratio in molecular-clou turbulence
title Supernova driving. II. Compressive ratio in molecular-clou turbulence
spellingShingle Supernova driving. II. Compressive ratio in molecular-clou turbulence
Pan, Liubin
Magnetohidrodinàmica
Turbulència
Formació d'estels
Magnetohydrodynamics
Turbulence
Star formation
title_short Supernova driving. II. Compressive ratio in molecular-clou turbulence
title_full Supernova driving. II. Compressive ratio in molecular-clou turbulence
title_fullStr Supernova driving. II. Compressive ratio in molecular-clou turbulence
title_full_unstemmed Supernova driving. II. Compressive ratio in molecular-clou turbulence
title_sort Supernova driving. II. Compressive ratio in molecular-clou turbulence
dc.creator.none.fl_str_mv Pan, Liubin
Padoan, Paolo
Haugbolle, Troels
Nordlund, Ake
author Pan, Liubin
author_facet Pan, Liubin
Padoan, Paolo
Haugbolle, Troels
Nordlund, Ake
author_role author
author2 Padoan, Paolo
Haugbolle, Troels
Nordlund, Ake
author2_role author
author
author
dc.subject.none.fl_str_mv Magnetohidrodinàmica
Turbulència
Formació d'estels
Magnetohydrodynamics
Turbulence
Star formation
topic Magnetohidrodinàmica
Turbulència
Formació d'estels
Magnetohydrodynamics
Turbulence
Star formation
description The compressibility of molecular cloud (MC) turbulence plays a crucial role in star formation models, because it controls the amplitude and distribution of density fluctuations. The relation between the compressive ratio (the ratio of powers in compressive and solenoidal motions) and the statistics of turbulence has been previously studied systematically only in idealized simulations with random external forces. In this work, we analyze a simulation of large-scale turbulence (250 pc) driven by supernova (SN) explosions that has been shown to yield realistic MC properties. We demonstrate that SN driving results in MC turbulence with a broad lognormal distribution of the compressive ratio, with a mean value approximate to 0.3, lower than the equilibrium value of approximate to 0.5 found in the inertial range of isothermal simulations with random solenoidal driving. We also find that the compressibility of the turbulence is not noticeably affected by gravity, nor are the mean cloud radial (expansion or contraction) and solid-body rotation velocities. Furthermore, the clouds follow a general relation between the rms density and the rms Mach number similar to that of supersonic isothermal turbulence, though with a large scatter, and their average gas density probability density function is described well by a lognormal distribution, with the addition of a high-density power-law tail when self-gravity is included.
publishDate 2016
dc.date.none.fl_str_mv 2016
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv https://hdl.handle.net/2445/148762
url https://hdl.handle.net/2445/148762
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.relation.none.fl_str_mv Reproducció del document publicat a: https://doi.org/10.3847/0004-637X/825/1/30
Astrophysical Journal, 2016, vol. 825, num. 1, p. 30
https://doi.org/10.3847/0004-637X/825/1/30
dc.rights.none.fl_str_mv (c) American Astronomical Society, 2016
info:eu-repo/semantics/openAccess
rights_invalid_str_mv (c) American Astronomical Society, 2016
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
dc.publisher.none.fl_str_mv Institute of Physics (IOP)
publisher.none.fl_str_mv Institute of Physics (IOP)
dc.source.none.fl_str_mv Articles publicats en revistes (Institut de Ciències del Cosmos (ICCUB))
reponame:Dipòsit Digital de la UB
instname:Universidad de Barcelona
instname_str Universidad de Barcelona
reponame_str Dipòsit Digital de la UB
collection Dipòsit Digital de la UB
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,300724

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