A disk model with gas pressure viscosity. The spectrum from an accretion disk where the viscosity scales as the gas pressure. From Stella and Rosner 1984, ApJ, 277, 312.

par1 |
accretion rate in Eddington Luminosities |

par2 |
central mass in solar mass units |

par3 |
inner disk radius in gravitational (= 3 Schwarzschild radii) |

par4 |
viscosity |

norm |
where i is the inclination of the disk and d is the distance in units of 10 kpc |