jfactor_small_angle_infinite_los#

jeanspy.model.NFWModel.jfactor_small_angle_infinite_los

Class and construction: NFWModel.

NFWModel.jfactor_small_angle_infinite_los(dist_pc, roi_deg=0.5)[source]#

Evaluate the small-angle, infinite-LOS Evans et al. (2016) formula.

This historical approximation caps the projected aperture at r_t_pc; it does not truncate the density along the line of sight. For a halo truncated in three dimensions use jfactor_cone instead.

Notes

Inputs and units. dist_pc in pc and roi_deg in degrees, positive finite broadcastable values; stored NFW scales/cutoff.

Returns and shape. J in GeV^2 cm^-5, with the broadcast input shape; scalar for scalar inputs.

Validity. Small-angle formula: the projected aperture is capped at r_t_pc but the LOS density is untruncated. It is a different integral from the three-dimensionally truncated finite-cone factor.