Observational Appearance and Spectrum of Black-Hole Winds with Supercritical Accretion Disks

摘要

Weexaminetheobservationalappearanceandexpectedspectraofanopticallythick,sphericallysymmetric,relativisticwind(ablack-holewind),blowingofffromthecentralregionofageometricallythicksupercriticalaccretiondisk.Duetotherelativisticlimb-darkening(center-brightening)effectaswellastheusualDopplerboost,theblack-holewindbecomesluminousasthewindspeedincreases.Wefoundthatthespectraoftheblack-holewindissomewhatsimilartoablackbodyone,whilethespectraofanakedsupercriticalaccretiondiskisknowntohaveaflatspectralenergydistribution(SED)whenviewingfromthepole-ondirection.Inthecaseofablack-holewindwithasupercriticalaccretiondisk,thespectragenerallybecomesahybridtype,butwefoundthatinalmostallcasesthecharacteristicflatSEDofasupercriticaldiskdisappears.Thatis,whenthespeedofthewindgasislow,theapparentphotosphereoftheblack-holewindbecomeslargerthanthesupercriticalregion.Inthiscasethespectraofablack-holewinddominates.Asthewindspeedincreases,theapparentphotosphereshrinksandthespectraofthediskemergent.However,whenthewindspeedbecomessufficientlyhigh,theinnerpartofthenakedsupercriticaldiskisnotseen,eveniftheinclinationangleissmall.