Cacciato09Cens

class halotools.empirical_models.Cacciato09Cens(threshold=10.0, prim_haloprop_key='halo_m180b', prim_galprop_key='luminosity', **kwargs)[source] [edit on github]

Bases: halotools.empirical_models.OccupationComponent

CLF-style model for the central galaxy occupation. Since it is a CLF model, it also assigns a primary galaxy property to galaxies in addition to effectively being an HOD model. The primary galaxy property can for example be luminosity or stellar mass.

See Cacciato et al. (2009) Composite Model for a tutorial on this model.

Parameters:

threshold : float, optional

Logarithm of the primary galaxy property threshold. If the primary galaxy property is luminosity, it is given in h=1 solar luminosity units.

prim_haloprop_key : string, optional

String giving the column name of the primary halo property governing the occupation statistics of central galaxies.

prim_galprop_key : string, optional

String giving the column name of the primary galaxy property that is assigned.

Examples

>>> cen_model = Cacciato09Cens()
>>> cen_model = Cacciato09Cens(threshold = 11.25)
>>> cen_model = Cacciato09Cens(prim_haloprop_key = 'halo_mvir')

Methods Summary

clf([prim_galprop, prim_haloprop]) Return the CLF in units of dn/dlogL for the primary halo property and galaxy property L.
get_published_parameters() Return the values of self.param_dict according to the best-fit values of the WMAP3 model in Table 3 of arXiv:0807.4932.
mc_prim_galprop(**kwargs) Method to generate Monte Carlo realizations of the primary galaxy property of galaxies under the constraint that the primary galaxy property is above the primary galaxy property threshold.
mean_occupation([prim_galprop_min]) Expected number of central galaxies in a halo.
median_prim_galprop(**kwargs) Return the median primary galaxy property of a central galaxy as a function of the input table.

Methods Documentation

clf(prim_galprop=10000000000.0, prim_haloprop=1000000000000.0)[source] [edit on github]

Return the CLF in units of dn/dlogL for the primary halo property and galaxy property L.

Parameters:

prim_haloprop : array_like, optional

Array of mass-like variable upon which the calculation is based.

prim_galprop : array_like, optional

Array of luminosity-like variable of the galaxy upon which the calculation is based.

Returns:

clf : array_like

Array containing the CLF in units of dN/dlogL. If prim_haloprop has only one element or is a scalar, the same primary halo property is assumed for all CLF values. Similarly, if prim_galprop has only one element or is a scalar, the same primary galaxy property is assumed throughout.

get_published_parameters()[source] [edit on github]

Return the values of self.param_dict according to the best-fit values of the WMAP3 model in Table 3 of arXiv:0807.4932. In this analysis, halo masses have been defined using an overdensity of 180 times the background density of the Universe.

mc_prim_galprop(**kwargs)[source] [edit on github]

Method to generate Monte Carlo realizations of the primary galaxy property of galaxies under the constraint that the primary galaxy property is above the primary galaxy property threshold.

Parameters:

prim_haloprop : array, optional

Array of mass-like variable upon which the primary galaxy properties 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.

seed : int, optional

Random number seed used to generate the Monte Carlo realization. Default is None.

Returns:

mc_prim_galprop : array

Float array giving the Monte Carlo realization of primary galaxy properties of centrals in halos of the given mass. All primary galaxy properties returned are above the threshold.

mean_occupation(prim_galprop_min=None, **kwargs)[source] [edit on github]

Expected number of central galaxies in a halo. Derived from integrating the CLF from the primary galaxy property threshold to infinity.

Parameters:

prim_galprop_min : float, optional

Lower limit of the CLF integration used to calculate the expected number of central galaxies. If not specified, the lower limit is the threshold.

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 halos of the input mass.

median_prim_galprop(**kwargs)[source] [edit on github]

Return the median primary galaxy property of a central galaxy as a function of the input table.

Parameters:

prim_haloprop : array, optional

Array of mass-like variable upon which the calculation is 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:

prim_galprop : array_like

Array containing the median primary galaxy property of the halos specified.