hearin15_model_dictionary

halotools.empirical_models.hearin15_model_dictionary(central_assembias_strength=1, central_assembias_strength_abscissa=[1000000000000.0], satellite_assembias_strength=0.2, satellite_assembias_strength_abscissa=[1000000000000.0], **kwargs)[source] [edit on github]

Dictionary to build an HOD-style model in which central and satellite occupations statistics are assembly-biased.

See Hearin et al. (2015) Composite Model for a tutorial on this model.

Parameters:

threshold : float, optional

Stellar mass threshold of the mock galaxy sample. Default value is specified in the model_defaults module.

redshift : float, optional

Default is set in the sim_defaults module.

sec_haloprop_key : string, optional

String giving the column name of the secondary halo property modulating the occupation statistics of the galaxies. Default value is specified in the model_defaults module.

central_assembias_strength : float or list, optional

Fraction or list of fractions between -1 and 1 defining the assembly bias correlation strength. Default is a constant strength of 0.5.

central_assembias_strength_abscissa : list, optional

Values of the primary halo property at which the assembly bias strength is specified. Default is a constant strength of 0.5.

satellite_assembias_strength : float or list, optional

Fraction or list of fractions between -1 and 1 defining the assembly bias correlation strength. Default is a constant strength of 0.5.

satellite_assembias_strength_abscissa : list, optional

Values of the primary halo property at which the assembly bias strength is specified. Default is a constant strength of 0.5.

split : float, optional

Fraction between 0 and 1 defining how we split halos into two groupings based on their conditional secondary percentiles. Default is 0.5 for a constant 50/50 split.

concentration_binning : tuple, optional

Three-element tuple. The first entry will be the minimum value of the concentration in the lookup table for the satellite NFW profile, the second entry the maximum, the third entry the linear spacing of the grid. Default is set in model_defaults. If high-precision is not required, the lookup tables will build much faster if concentration_binning is set to (1, 25, 0.5).

Examples

>>> model_dictionary = hearin15_model_dictionary()
>>> model_instance = factories.HodModelFactory(**model_dictionary)

The default settings are set in the model_defaults module. To load a model based on a different threshold and redshift:

>>> model_dictionary = hearin15_model_dictionary(threshold = 11, redshift = 1)
>>> model_instance = factories.HodModelFactory(**model_dictionary)

For this model, you can also use the following syntax candy, which accomplishes the same task as the above:

>>> model_instance = factories.PrebuiltHodModelFactory('hearin15', threshold = 11, redshift = 1)

As with all instances of the PrebuiltHodModelFactory, you can populate a mock by passing the model a halo catalog:

>>> from halotools.sim_manager import FakeSim
>>> halocat = FakeSim(redshift = model_instance.redshift)
>>> model_instance.populate_mock(halocat)