Leauthaud11Sats

class halotools.empirical_models.Leauthaud11Sats(threshold=10.5, prim_haloprop_key='halo_mvir', redshift=0.0, modulate_with_cenocc=True, cenocc_model=None, **kwargs)

Bases: OccupationComponent

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

Note

The Leauthaud11Sats 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.

modulate_with_cenoccbool, optional

If True, the first satellite moment will be multiplied by the the first central moment. Default is True.

cenocc_modelOccupationComponent, optional

If the cenocc_model keyword argument is set to its default value of None, then the \(\langle N_{\mathrm{cen}}\rangle_{M}\) prefactor will be calculated according to leauthaud11Cens.mean_occupation. However, if an instance of the OccupationComponent class is instead passed in via the cenocc_model keyword, then the first satellite moment will be multiplied by the mean_occupation function of the cenocc_model. The modulate_with_cenocc keyword must be set to True in order for the cenocc_model to be operative. See Advanced usage of the zheng07 model for further details.

Examples

>>> sat_model = Leauthaud11Sats()

Methods Summary

mean_occupation(**kwargs)

Expected number of satellite galaxies in a halo of mass halo_mass.

Methods Documentation

mean_occupation(**kwargs)

Expected number of satellite galaxies in a halo of mass halo_mass. See Equation 12-14 of arXiv:1103.2077.

Parameters:

prim_haloproparray, optional

array of masses of table in the catalog

tableobject, optional

Data table storing halo catalog.

Returns:

mean_nsatarray

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

Notes

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

Examples

>>> sat_model = Leauthaud11Sats()
>>> mean_nsat = sat_model.mean_occupation(prim_haloprop = 1.e13)