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

Bases: OccupationComponent

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


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.

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.


>>> sat_model = Leauthaud11Sats()

Methods Summary


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

Methods Documentation


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

prim_haloproparray, optional

array of masses of table in the catalog

tableobject, optional

Data table storing halo catalog.


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


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


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