Self-irradiated funnel

NOTE: This model is now in the Xspec release and this page is superceded by the Xspec manual

The multiblackbody "Self-IrRdaiated Funnel" model is designed to model optically-thick outflow-dominated accretion. The basic idea is simple: you just assume a lot of matter, angular momentum and energy emerges in a limited volume. Momentum conservation leads to non-sphericity of the flow that has subsequently conical (funnel-like) shape. The model calculates temperature distribution at the funnel walls (taking into account irradiation by iterative process) and the outer photosphere. We also assume that inside the cone there is a deep pseudo-photosphere. Relativistic boosts are taken into account for high velocities. For a comprehensive description of the physical model, see: Abolmasov, P., Karpov, S. and Kotani, T. PASJ, 61, 2, 213.

par1 = tin, inner temperature (at the inner, inside-the-funnel photosphere).
par2 = rin, inner (inside-the-funnel photosphere) radius in "spherisation radius" units (the latter is defined as 3 Κ Mdot / Ωf c).
par3 = rout, outer photosphere radius in "spherisation radius" units.
par4 = theta, half-opening angle of the cone.
par5 = incl, inclination angle of the funnel. Affects mainly self-occultation and relativistic boost effects.
par6 = valpha, velocity law exponent, v goes as rvalpha.
par7 = gamma, adiabate index. It affects the inner, hotter parts of the flow, therefore we set is to 4/3 by default.
par8 = mdot, mass ejection rate in Eddington (critical) units.
par9 = irrad, number of iterations for irradiation.

The source code file required is sirf.cpp with the parameter information in lmodel_sirf.dat.

Keith Arnaud, Lab. for High Energy Astrophysics, NASA/Goddard Space Flight Center

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Last modified: Tuesday, 14-Feb-2023 16:42:01 EST