Magnetorotational Collapse of Population III Stars

[摘要] Weperformedaseriesoftwo-dimensionalmagnetorotationalcore-collapsesimulationsofPopulationIIIstars.Changingtheinitialdistributionsoftherotationandmagneticfieldspriortocollapseinaparametricmanner,wecomputed19models.Bysodoing,wesystematicallyinvestigatedhowrotationandmagneticfieldsaffectthecollapsedynamics,andexploredhowthepropertiesofblack-holeformationsandneutrinoemissionscouldbeaffected.Asformicrophysics,weemployedarealisticequationofstate,andapproximatedneutrinotransferbyamultiflavourleakagescheme.Withthesecomputations,wefoundthatjet-likeexplosionsareobtainedbymagneto-drivenshockwavesiftheinitialmagneticfieldisaslargeas$$10^{12}$$G.Wepointoutthatalthoughtheblack-holemassesatformationdecreasewiththeinitialfieldstrength,theyincreasewiththeinitialrotationrates.Asfortheneutrinoproperties,wepointoutthatthedegreeofdifferentialrotationplaysanimportantroleindeterminingwhichspeciesoftheneutrinoluminosityismoredominantthantheothers.Furthermore,wefindthatstrongermagneticfieldsmakethepeakneutrinoluminositiessmaller,becausethemagneticpressureactstohaltcollapseinthecentralregions,leadingtoasuppressionofthereleasablegravitationalbindingenergies.

[学科分类] 天文学(综合)

[关键词] "supernovae: general";"black hole physics";neutrinos;"methods: numerical";"magnetohydrodynamics (MHD)"