Hydrodynamical Study of Neutrino-Driven Wind as an r-Process Site
[摘要] Wediscusstheneutrino-drivenwindfromaproto-neutronstarbasedongeneral-relativistichydro-dynamicalsimulations.Weexaminethepropertiesoftheneutrino-drivenwindtoexplorethepossibilityofr-processnucleosynthesis.Numericalsimulationsinvolvingneutrinoheatingandcoolingprocesseswereperformedwiththeassumptionofaconstantneutrinoluminositybyusingrealisticprofilesoftheproto-neutronstar(PNS)aswellassimplifiedmodels.ThedependenceonthemassofPNSandtheneutrinoluminosityispresentedsystematically.Comparisonswithanalytictreatmentsinthepreviousstudiesarealsogiven.InthecaseswiththerealisticPNS,wehavefoundthattheentropyperbaryonandtheexpansiontimescaleareneitherhighnorshortenoughforther-processwithinthecurrentassumptions.Ontheotherhand,wehavealsofoundthattheexpansiontimescaleobtainedbyhydrodynamicalsimulationsissystematicallyshorterthanthatintheanalyticsolutionsduetoourpropertreatmentoftheequationofstate.Thisfactmightleadtoanincreaseintheneutron-to-seedratio,whichissuitableforther-processinaneutrino-drivenwind.Indeed,inthecaseofmassiveandcompactproto-neutronstarswithhighneutrinoluminosities,theexpansiontimescaleisfoundtobesufficientlyshortinhydrodynamicalsimulations,andther-processelementsuptoA∼200areproducedinther-processnetworkcalculation.
[发布日期] [发布机构]
[效力级别] [学科分类] 天文学(综合)
[关键词] "hydrodynamical simulation";"neutrino-driven winds";nucleosynthesis;"stars: neutron" [时效性]
