density_threshold¶
- halotools.empirical_models.density_threshold(cosmology, redshift, mdef)[source]¶
The threshold density for a given spherical-overdensity mass definition.
\(\rho_{\rm thresh}(z) = \Delta_{\rm ref}(z)\rho_{\rm ref}(z)\).
See Halo Mass and Radius Definitions for details.
- Parameters:
- cosmologyobject
Instance of an Astropy
cosmology
object.- redshift: array_like
Can be a scalar or a numpy array.
- mdef: str
String specifying the halo mass definition, e.g., ‘vir’ or ‘200m’.
- Returns:
- rho: array_like
The threshold density in physical \(M_{\odot}h^2/Mpc^3\). Has the same dimensions as the input
redshift
.
See also
delta_vir
The virial overdensity in units of the critical density.