Basic Properties of Supercritical Accretion Disks

[摘要] Attheturnofthemillennium,supercriticalaccretiondisks(superdisks),wherethemass-accretionratehighlyexceedstheEddington'sone,arebeingresurrectedunderrecentobservationalandtheoreticalprogress.Weexaminedtheeffectsandpropertiesoftheself-irradiation,self-occultation,continuousandlinespectraofsuperdisks,andfoundvariousdistinctfeaturesofsuperdisks.Duetoself-irradiation,theeffectivefluxisenhancedbyafactorof1.1to1.8alloverthedisk,dependingontherelativediskthickness.Forasuperdiskwithfinitethickness,thefluxatinfinityisenhancedinthepolewarddirection,whileitiszerointheequatorialdirection.Thecontinuousspectraaregenerallyflat(vSv∼v0),aslongasweseethediskpole-on.It,however,stronglydependsontheinclinationangle:foralargerinclinationanglethecentralpartofthediskisself-occultedandtheflatnatureofthecontinuumdisappears.Thelinespectraarealsogreatlymodifiedfromthoseofthestandarddisk.Inthenon-relativisticstandardmodelthelinespectrahavesymmetricaldoublepeaks.Inthesuperdisk,however,thelinespectrabecomeasymmetricwithstrongbluepeaksandweakredpeaks,evenforthenon-relativisticcase.Thisisduetotheprojectioneffect.Therelationsbetweentheobservablesandmodelparametersarederived.

[学科分类] 天文学(综合)

[关键词] "accretion;accretion disks";"black holes";"galaxies: active";"line: profiles";"X-rays: stars"