Self-Gravitational Instability of an Isothermal Gaseous Slab under High External Pressure

Publications of the Astronomical Society of Japan

Matsumoto, Ryoji³  Yoshida, Tatsuo²  Miyaji, Shigeki³  Umekawa, Michihisa¹ 

[1] Graduate School of Science and Technology, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, Chiba 263-8522 E-mail (MU):;Department of Physics, Faculty of Science, Ibaraki University, 2-1-1 Bunkyo, Mito, Ibaraki 310-8512;Department of Physics, Faculty of Science, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba, Chiba 263-8522

关键词: Hydrodynamics;    Instabilities;    "Interstellar: clouds";    "Stars: formation";   

DOI  :  10.1093/pasj/51.5.625

学科分类：天文学(综合)

来源: Oxford University Press

【 摘 要 】

Wecarriedouttwo-dimensionalhydrodynamicsimulationstostudythenonlineargrowthofthegravitationalinstabilityofaself-gravitatingisothermalgaseousslabconfinedbyexternalpressure.Whentheexternalpressureislow,theJeansinstabilitycreatesdensecollapsingclumpsforlong-wavelengthperturbations.Whentheexternalpressureishigh(Pext/P00gt;0.64whereP00istheinitialmid-planepressureandPextistheexternalpressure),anincompressiblemodeofgravitationalinstabilitycreatesclumps,themassofwhichissmallerthantheJeansmass.Theclumpsmergeduetomutualgravitationalattraction.Althougheachclumpcannotcollapsegravitationally,whenitsmassexceedstheJeansmassbymerging,themergedclumpcollapsesgravitationally.Theseresultsindicatethatwhentheexternalpressureishigh,starformationcanbetriggeredbythemergingoflow-massJeansstableclumps.Inhighexternalpressureregions,weexpectthatthemassfunctionofcollapsingclumpsinthecloudshasapeakaroundtheJeansmass.

【 授权许可】

Unknown