# Cacciato09Sats¶

class halotools.empirical_models.Cacciato09Sats(threshold=10.0, prim_haloprop_key='halo_m180b', prim_galprop_key='luminosity', **kwargs)[source] [edit on github]

CLF-style model for the satellite 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: 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 satellite galaxies. prim_galprop_key : string, optional String giving the column name of the primary galaxy property that is assigned.

Examples

>>> sat_model = Cacciato09Sats()
>>> sat_model = Cacciato09Sats(threshold = 11.25)
>>> sat_model = Cacciato09Sats(prim_haloprop_key = 'halo_mvir')


Methods Summary

 alpha_sat(**kwargs) Return the power-law slope of the CLF as a function of the input table. clf([prim_galprop, prim_haloprop]) Return the CLF in units of dn/dlogL for the primary halo property and galaxy property L. get_default_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 satellite galaxies in a halo. phi_sat(**kwargs) Return the normalization for the CLF as a function of the input table. prim_galprop_cut(**kwargs) Return the cut-off primary galaxy properties of the CLF as a function of the input table.

Methods Documentation

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

Return the power-law slope of the CLF 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. alpha_sat : array_like Array containing the CLF power-law slopes of the halos specified.
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. 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_default_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. mc_prim_galprop : array Float array giving the Monte Carlo realization of primary galaxy properties of satellites in halos of the given mass. All primary galaxy properties returned are above the threshold.
mean_occupation(prim_galprop_min=None, prim_galprop_max=None, **kwargs)[source] [edit on github]

Expected number of satellite galaxies in a halo. Derived from integrating the CLF from the luminosity threshold to infinity.

Parameters: prim_galprop_min : float, optional Lower limit of the CLF integration used to calculate the expected number of satellite galaxies. If not specified, the lower limit is the threshold. prim_galprop_max : float, optional Upper limit of the CLF integration used to calculate the expected number of satellite galaxies. If not specified, the upper limit is infinity. 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. mean_nsat : array Mean number of satellite galaxies in the halo of the input mass.
phi_sat(**kwargs)[source] [edit on github]

Return the normalization for the CLF as a function of the input table. See equation (36) in Cacciato et al. (2009) for details. The normalization refers to $phi_s^star$.

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. phi_sat : array_like Array containing the CLF normalization values of the halos specified.
prim_galprop_cut(**kwargs)[source] [edit on github]

Return the cut-off primary galaxy properties of the CLF as a function of the input table. See equation (38) in Cacciato et al. (2009) for details. The cut-off primary galaxy property refers to $L_s^star$.

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. prim_galprop_cut : array_like Array containing the cut-off primary galaxy property of the halos specified.