Leauthaud11Cens

class halotools.empirical_models.Leauthaud11Cens(threshold=10.5, prim_haloprop_key='halo_mvir', redshift=0.0, **kwargs)

Bases: OccupationComponent

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

Note

The Leauthaud11Cens model is part of the leauthaud11 prebuilt composite HOD-style model. For a tutorial on the leauthaud11 composite model, see Leauthaud et al. (2011) Composite Model.

Parameters:

thresholdfloat, optional

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

Values in the Leauthaud11 parameter dictionary are quoted assuming h=0.72, so that a direct comparison can be made to the best-fitting values quoted in Leauthaud+11. However, the threshold of the sample in halotools is defined assuming h=1. This means that in order to compare your parameter dictionary to the best-fitting parameters in Leauthaud+11, you will need to compare to the appropriately scaled threshold. For example, in Figure 2 of arXiv:1103.2077, the most massive sample is labeled logsm>11.4. In Halotools, this corresponds to threshold=11.115.

prim_haloprop_keystring, optional

String giving the column name of the primary halo property governing the occupation statistics of gal_type galaxies. Default value is specified in the model_defaults module.

redshiftfloat, optional

Redshift of the stellar-to-halo-mass relation. Default is set in sim_defaults.

Examples

>>> cen_model = Leauthaud11Cens()
>>> cen_model = Leauthaud11Cens(threshold = 11.25)
>>> cen_model = Leauthaud11Cens(prim_haloprop_key = 'halo_m200b')

Methods Summary

get_published_parameters()	Return the values of self.param_dict according to the SIG_MOD1 values of Table 5 of arXiv:1104.0928 for the lowest redshift bin.
mean_log_halo_mass(log_stellar_mass_h1p0)	Return the base-10 logarithm of the halo mass of a central galaxy as a function of the base-10 logarithm 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()

Return the values of self.param_dict according to the SIG_MOD1 values of Table 5 of arXiv:1104.0928 for the lowest redshift bin.

mean_log_halo_mass(log_stellar_mass_h1p0)

Return the base-10 logarithm of the halo mass of a central galaxy as a function of the base-10 logarithm of the input stellar mass.

Parameters:

log_stellar_mass_h1p0array

Array of base-10 logarithm of stellar masses in h=1 solar mass units.

Note that throughout Leauthaud+11 it is assumed that h=0.72. As a sanity check on your conversion: logsm_h0p72 = logsm_h1p0 - 2*log10(0.72) So that logsm_h0p72 is larger than logsm_h1p0

Returns:

log_halo_mass_h1p0array_like

Array containing 10-base logarithm of halo mass in h=1 solar mass units.

Note that throughout Leauthaud+11 it is assumed that h=0.72. As a sanity check on your conversion: log_halo_mass_h0p72 = log_halo_mass_h1p0 - log10(0.72) So that log_halo_mass_h0p72 is larger than log_halo_mass_h1p0

mean_occupation(**kwargs)

Expected number of central galaxies in a halo. See Equation 8 of arXiv:1103.2077.

Parameters:

prim_haloproparray, 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.

tableobject, optional

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

Returns:

mean_ncenarray

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

Notes

Assumes constant scatter in the stellar-to-halo-mass relation.

mean_stellar_mass(**kwargs)

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

Parameters:

prim_haloproparray, 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.

tableobject, optional

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

Returns:

mstar_h1p0array_like

Array containing stellar masses in units of h=1

Note that throughout Leauthaud+11 it is assumed that h=0.72. As a sanity check on your conversion: mstar_h0p72 = mstar_h1p0/0.5184 So that mstar_h0p72 is larger than mstar_h1p0