Method

NumCosmoDistancesigma_critical

Declaration [src]

gdouble
nc_distance_sigma_critical (
  NcDistance* dist,
  NcHICosmo* cosmo,
  const gdouble zs,
  const gdouble zl
)

Description [src]

Computes the critical surface density, \begin{equation}\label{eq:def:SigmaC} \Sigma_c = \frac{c^2}{4\pi G} \frac{D_s}{D_l D_{ls}}, \end{equation} where $c^2$ is the speed of light squared [ncm_c_c2 ()], $G$ is the gravitational constant in units of $m^3/s^2 M_\odot^{-1}$ [ncm_c_G_mass_solar()], $D_s$ ($D_l$) is the angular diameter distance from the observer to the source (lens), and $D_{ls}$ is the angular diameter distance between the lens and the source.

Parameters

cosmo

Type: NcHICosmo

A NcHICosmo.

The data is owned by the caller of the method.

zs

Type: const gdouble

Source redshift $z_\mathrm{source}$.

zl

Type: const gdouble

Lens redshift $z_\mathrm{lens}$.

Return value

Type: gdouble

The critical surface density $\Sigma_c$ in units of $M_\odot / Mpc^2$.