Encounters
Boundary Value Problem ○꠹｜encounter｜ENC｜20260912001826-00-•
The cardinal importance of the inner disk region highlights the need for an accurate model for the radiation emitted near the inner disk boundary associated with the ISCO (see §1). The ISCO lies at for a Schwarzschild BH (), decreasing toward as approaches 1. Observationally, the thermal-state spectra of BHBs are well fitted using the classical model for a multitemperature accretion disk (Mitsuda et al. 1984; Makishima et al. 1986; Kubota & Makishima 2004; Kubota et al. 2005). However, the derived spectral parameters (i.e., the temperature and radius of the inner disk) cannot be interpreted literally for several reasons. The model neglects the physically-motivated torque-free boundary condition at the ISCO (see Gierlinski et al. 2001; Zimmerman et al. 2005). Furthermore, the classical model ignores the sizable effects due to GR and radiative transfer (e.g., see Zhang, Cui, & Chen 1997). Fortunately, accretion disk models for Kerr BHs have recently become publicly available (Li et al. 2005; Dovciak et al. 2005), and there now exists a fully-relativistic treatment of the effects of spectral hardening (Davis et al. 2005). Applications of these models are discussed in §8.
Source: Remillard & McClintock 2006 ┃ X-Ray Properties… ⚬𓂃
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