virial_coeff_tot

deprojected_sersic_models.utils.virial_coeff_tot(R, total_mass=1.0, vc=None)

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

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

to convert between the circular velocity at any given radius and the total system mass.

Parameters:

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

• total_mass (float) – Total mass of the component [Msun]

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

Returns:

ktot – ktot = Mtot * G / (vcirc(R)^2 * R)

Return type:

float or array_like