# smhm_binary_sfr_model_dictionary¶

halotools.empirical_models.smhm_binary_sfr_model_dictionary(prim_haloprop_key='halo_mpeak', smhm_model=<class 'halotools.empirical_models.smhm_models.behroozi10.Behroozi10SmHm'>, scatter_level=0.2, redshift=0.0, sfr_abscissa=[12, 15], sfr_ordinates=[0.25, 0.75], logparam=True, **kwargs)[source] [edit on github]

Dictionary to build a subhalo-based model for both stellar mass and star-formation rate.

Stellar masses are based on Behroozi10SmHm by default. SFR-designation is binary and is based on an input quenched fraction as a function of some halo property such as virial mass. In particular, SFR designation is determined by interpolating between a set of input control points, with default behavior being a 25% quiescent fraction for galaxies residing in Milky Way halos, and 75% for cluster galaxies.

Since smhm_binary_sfr_model_dictionary does not discriminate between centrals and satellites in the SFR assignment, this model is physically unrealistic and is included here primarily for demonstration purposes.

Parameters: prim_haloprop_key : string, optional String giving the column name of the primary halo property governing the galaxy propery being modeled. Default is set in the model_defaults module. smhm_model : object, optional Sub-class of PrimGalpropModel governing the stellar-to-halo-mass relation. Default is Behroozi10SmHm. scatter_level : float, optional Constant amount of scatter in stellar mass, in dex. Default is 0.2. redshift : float, optional Redshift of the halo hosting the galaxy. Used to evaluate the stellar-to-halo-mass relation. Default is set in sim_defaults. sfr_abscissa : array, optional Values of the primary halo property at which the quiescent fraction is specified. Default is [12, 15], in accord with the default True value for logparam. sfr_ordinates : array, optional Values of the quiescent fraction when evaluated at the input abscissa. Default is [0.25, 0.75] logparam : bool, optional If set to True, the interpolation will be done in the base-10 logarithm of the primary halo property, rather than linearly. Default is True. threshold : float, optional Stellar mass threshold of mock galaxy catalog. Default is None, in which case the lower bound on stellar mass will be entirely determined by the resolution of the N-body simulation and the model parameters. model : object Instance of SubhaloModelFactory

Examples

>>> from halotools.empirical_models import SubhaloModelFactory
>>> model_dictionary = smhm_binary_sfr_model_dictionary()
>>> model_instance = SubhaloModelFactory(**model_dictionary)