calc_radius

luminet.black_hole_math.calc_radius(p: float, ir_angle: float, bh_mass: float, incl: float, order: int = 0) → float

Calculate the radius on the black hole accretion disk from a photon’s periastron value.

Parameters:

  • p (float) – Periastron distance. This is directly related to the observer coordinate frame \(b\)

  • ir_angle (float) – Angle of the observer/bh coordinate frame.

  • bh_mass (float) – Black hole mass

  • incl (float) – Inclination of the black hole

  • order (int) – Order of the image. Default is \(0\) (direct image).

Attention

This is not the equation used to solve for the periastron value \(P\). For the equation that is optimized in order to convert between black hole and observer frame, see periastron_optimization_function().

Returns:

float – Black hole frame radius \(r\) of the photon trajectory.