virial_coeff_3D

deprojected_sersic_models.utils.virial_coeff_3D(R, m3D=None, vc=None)

Evalutation of the “total” virial coefficient ktot, which satisfies

\[\begin{split}M_{\mathrm{3D,sphere}} = k_{\mathrm{3D}}(R) \\frac{v_{\mathrm{circ}}(R)^2 R}{ G },\end{split}\]

to convert between the circular velocity at any given radius and the mass enclosed within a sphere of radius r=R.

Parameters:

• R (float or array_like) – Major axis radius at which to evaluate virial coefficient [kpc]

• m3D (float or array_like) – Pre-calculated evaluation of Menc3D_sphere(R) (saves time to avoid recalculating Menc3D_sphere(R)) [Msun]

• vc (float or array_like) – Pre-calculated evaluation of vcirc(R) (saves time to avoid recalculating vcirc(R)) [km/s]

Returns:

k3D – k3D = Menc3D_sphere(R) * G / (vcirc(R)^2 * R)

Return type:

float or array_like