Apparent Photosphere of Massive Accretion-Disk Winds

[摘要] Weexaminedtheobservationalappearanceofhighlyopticallythickwindsfromsupercriticalaccretiondisks,whileespeciallyfocusingontheshapeofa“photosphere”ofthewind.Whenamassivewindblowsfromanaccretiondisk,theopticaldepthofthewindmayexceedunityintheplace,whichishigherthanthescaleheightofthedisk.Ifsuchawindisrealized,theobservedlightmayhaveoriginatedfromthephotosphereofthewind,ratherthanfromthedisksurface.Wecalculatedtheapparentsurfaceofthephotosphere,wheretheobservedopticaldepthisunity,andcompareditwiththegeometryoftheaccretiondisk.Wefoundthatthewindphotospherecanexpandoverthediskscale-heightforsuper-Eddingtonmass-lossrates,butthelocationandappearanceofthephotospherestronglydependontheinclinationangleaswellasthemass-lossrate.Thisfactmayaffectontheinterpretationoflightcurvesingalacticeclipsingbinariesandrecentlywell-observedultraluminousX-raysources.

[学科分类] 天文学(综合)

[关键词] "accretion;accretion disks";"black hole physics";"stars: winds;outflows";"X-rays: stars"