TrivialProfile

class halotools.empirical_models.TrivialProfile(cosmology=FlatLambdaCDM(name="WMAP5", H0=70.2 km / (Mpc s), Om0=0.277, Tcmb0=2.725 K, Neff=3.04, m_nu=[ 0. 0. 0.] eV, Ob0=0.0459), redshift=0.0, mdef='vir', **kwargs)[source] [edit on github]

Bases: halotools.empirical_models.AnalyticDensityProf

Profile of dark matter halos with all their mass concentrated at exactly the halo center.

Parameters:

cosmology : object, optional

Astropy cosmology object. Default is set in sim_defaults.

redshift : float, optional

Default is set in sim_defaults.

mdef: str, optional

String specifying the halo mass definition, e.g., ‘vir’ or ‘200m’. Default is set in model_defaults.

Examples

You can load a trivial profile model with the default settings simply by calling the class constructor with no arguments:

>>> trivial_halo_prof_model = TrivialProfile()

Methods Summary

dimensionless_mass_density(scaled_radius, …) Physical density of the halo scaled by the density threshold of the mass definition.
enclosed_mass(radius, total_mass) The mass enclosed within the input radius, \(M(<r) = 4\pi\int_{0}^{r}dr'r'^{2}\rho(r)\).

Methods Documentation

dimensionless_mass_density(scaled_radius, total_mass)[source] [edit on github]

Physical density of the halo scaled by the density threshold of the mass definition.

The dimensionless_mass_density is defined as \(\tilde{\rho}_{\rm prof}(\tilde{r}) \equiv \rho_{\rm prof}(\tilde{r}) / \rho_{\rm thresh}\), where \(\tilde{r}\equiv r/R_{\Delta}\).

Parameters:

scaled_radius : array_like

Halo-centric distance r scaled by the halo boundary \(R_{\Delta}\), so that \(0 <= \tilde{r} \equiv r/R_{\Delta} <= 1\). Can be a scalar or numpy array.

total_mass: array_like

Total halo mass in \(M_{\odot}/h\); can be a number or a numpy array.

Returns:

dimensionless_density: array_like

Dimensionless density of a dark matter halo at the input scaled_radius, normalized by the density_threshold \(\rho_{\rm thresh}\) for the halo mass definition, cosmology, and redshift. Result is an array of the dimension as the input scaled_radius.

enclosed_mass(radius, total_mass)[source] [edit on github]

The mass enclosed within the input radius, \(M(<r) = 4\pi\int_{0}^{r}dr'r'^{2}\rho(r)\).

For the TrivialProfile, this is equal to the total mass of the halo for all non-zero radii.

Parameters:

radius : array_like

Halo-centric distance in Mpc/h units; can be a scalar or numpy array

total_mass : array_like

Total mass of the halo; can be a scalar or numpy array of the same dimension as the input radius.

Returns:

enclosed_mass: array_like

The mass enclosed within radius r, in \(M_{\odot}/h\); has the same dimensions as the input radius.