craftutils.wrap.galfit.b_func(r_in: Quantity, r_out: Quantity, theta_out: Quantity)

Calculates the value B as defined in Galfit User’s Manual, Appendix A (Peng 2010) :param r_in: Spiral inner radius, in pixels. If this goes extremely negative in fitting, fix to 0.

Corresponds to item R1) in the GALFIT feedme definition.

Parameters
r_out: Quantity

Spiral outer radius, in pixels. Corresponds to item R2) in the GALFIT feedme definition.

theta_out: Quantity

Cumulative rotation to outer radius, in degrees. Corresponds to item R3) in the GALFIT feedme definition.

Returns

B, in radians