ZuMandelbaum15Cens

class halotools.empirical_models.ZuMandelbaum15Cens(threshold=10.5, prim_haloprop_key='halo_m200m', **kwargs)[source] [edit on github]

Bases: halotools.empirical_models.OccupationComponent

HOD-style model for any central galaxy occupation that derives from a stellar-to-halo-mass relation.

Note

The ZuMandelbaum15Cens model is part of the zu_mandelbaum15 prebuilt composite HOD-style model. For a tutorial on the zu_mandelbaum15 composite model, see Zu & Mandelbaum et al. (2015) Composite Model.

Parameters:

threshold : float, optional

Stellar mass threshold of the mock galaxy sample in h=1 solar mass units. Default value is specified in the model_defaults module.

prim_haloprop_key : string, optional

String giving the column name of the primary halo property governing the occupation statistics of gal_type galaxies. Default value is halo_m200m, as in Zu & Mandelbaum (2015)

redshift : float, optional

Redshift of the stellar-to-halo-mass relation. Default is z=0.

Notes

Note also that the best-fit parameters of this model are based on the halo_m200m halo mass definition. Using alternative choices of mass definition will require altering the model parameters in order to mock up the same model published in Zu & Mandelbaum 2015. The Colossus python package written by Benedikt Diemer can be used to convert between different halo mass definitions. This may be useful if you wish to use an existing halo catalog for which the halo mass definition you need is unavailable.

Examples

>>> cen_model = ZuMandelbaum15Cens()
>>> cen_model = ZuMandelbaum15Cens(threshold=11.25)
>>> cen_model = ZuMandelbaum15Cens(prim_haloprop_key='halo_m200b')

Methods Summary

get_published_parameters()
mean_halo_mass(stellar_mass) Return the halo mass of a central galaxy as a function of the input stellar mass.
mean_occupation(**kwargs) Expected number of central galaxies in a halo.
mean_stellar_mass(**kwargs) Return the stellar mass of a central galaxy as a function of the input table.

Methods Documentation

get_published_parameters()[source] [edit on github]
mean_halo_mass(stellar_mass)[source] [edit on github]

Return the halo mass of a central galaxy as a function of the input stellar mass.

Parameters:

stellar_mass : array

Array of stellar masses in h=1 solar mass units.

Returns:

halo_mass : array_like

Array containing halo mass in h=1 solar mass units.

Examples

>>> cen_model = ZuMandelbaum15Cens(threshold=10.75)
>>> stellar_mass = np.logspace(9, 12, 25)
>>> halo_mass = cen_model.mean_halo_mass(stellar_mass)
mean_occupation(**kwargs)[source] [edit on github]

Expected number of central galaxies in a halo.

Parameters:

prim_haloprop : array, optional

Array of mass-like variable upon which occupation statistics are based. If prim_haloprop is not passed, then table keyword argument must be passed.

table : object, optional

Data table storing halo catalog. If table is not passed, then prim_haloprop keyword argument must be passed.

Returns:

mean_ncen : array

Mean number of central galaxies in the halo of the input mass.

Examples

>>> cen_model = ZuMandelbaum15Cens(threshold=10.75)
>>> halo_masses = np.logspace(11, 15, 25)
>>> mean_ncen = cen_model.mean_occupation(prim_haloprop=halo_masses)
mean_stellar_mass(**kwargs)[source] [edit on github]

Return the stellar mass of a central galaxy as a function of the input table.

Parameters:

prim_haloprop : array, optional

Array of mass-like variable upon which occupation statistics are based. If prim_haloprop is not passed, then table keyword argument must be passed.

table : object, optional

Data table storing halo catalog. If table is not passed, then prim_haloprop keyword argument must be passed.

Returns:

mstar : array_like

Array containing stellar masses living in the input table.

Examples

>>> cen_model = ZuMandelbaum15Cens(threshold=10.75)
>>> halo_masses = np.logspace(11, 15, 25)
>>> mstar = cen_model.mean_stellar_mass(prim_haloprop=halo_masses)