NAME:
rvir
PURPOSE:
calculate the virial radius for this density distribution
INPUT:
vo - velocity unit in km/s
ro - length unit in kpc
H= (default: 70) Hubble constant in km/s/Mpc
Om= (default: 0.3) Omega matter
overdens= (200) overdensity which defines the virial radius
wrtcrit= (False) if True, the overdensity is wrt the critical density rather than the mean matter density
OUTPUT:
virial radius in natural units
HISTORY:
2014-01-29 - Written - Bovy (IAS)