Bases: halotools.halo_occupation.HOD_Quenching_Model
Subclass of HOD_Quenching_Model, providing a traditional HOD model of galaxy quenching, in which quenching designation is purely determined by host halo virial mass.
Approach is adapted from van den Bosch 2003. The desired quenched fraction is specified at a particular set of masses, and the code then uses the unique, minimal-degree polynomial passing through those points to determine the quenched fraction at any mass. The desired quenched fraction must be independently specified for centrals and satellites.
Notes
All-galaxy central and satellite occupation statistics are specified first; Zheng07_HOD_Model is the default choice, but any supported HOD_Mock object could be chosen. A quenching designation is subsequently applied to the galaxies. Thus in this class of models, the central galaxy SMHM has no dependence on quenched/active designation.
Attributes Summary
| baseline_hod_model | |
| primary_halo_property_key |
Methods Summary
| mean_concentration(primary_halo_property, ...) | Concentration-mass relation assumed by the underlying HOD_Model object. |
| mean_ncen(primary_halo_property, halo_type) | Expected number of central galaxies in a halo of mass logM. |
| mean_nsat(primary_halo_property, halo_type) | Expected number of satellite galaxies in a halo of mass logM. |
| mean_quenched_fraction_centrals(...) | Expected fraction of centrals that are quenched as a function of host halo mass logM. |
| mean_quenched_fraction_satellites(...) | Expected fraction of satellites that are quenched as a function of host halo mass logM. |
| quenching_polynomial_model(abcissa, ...) | |
| require_correct_keys(quenching_parameter_dict) |
Attributes Documentation
Methods Documentation
Concentration-mass relation assumed by the underlying HOD_Model object. The appropriate method is already bound to the self.hod_model object.
| Parameters: | logM : array
halo_type : array
|
|---|---|
| Returns: | concentrations : array |
Expected number of central galaxies in a halo of mass logM. The appropriate method is already bound to the self.hod_model object.
| Parameters: | logM : array
halo_type : array
|
|---|---|
| Returns: | mean_ncen : float or array
|
Expected number of satellite galaxies in a halo of mass logM. The appropriate method is already bound to the self.hod_model object.
| Parameters: | logM : array
halo_type : array
|
|---|---|
| Returns: | mean_nsat : float or array
|
Expected fraction of centrals that are quenched as a function of host halo mass logM. A required method for any HOD_Quenching_Model object.
| Parameters: | logM : array_like
halo_type : array
|
|---|---|
| Returns: | mean_quenched_fractions : array_like
|
Notes
The model assumes the quenched fraction is a polynomial in logM. The degree N quenching polynomial is determined by solving for the unique polynomial with values given by the central quenching ordinates at the logM abcissa. The coefficients of this polynomial are solved for by the solve_for_quenching_polynomial_coefficients method. This function assumes that these coefficients have already been solved for and bound to the input object as an attribute.
Expected fraction of satellites that are quenched as a function of host halo mass logM. A required method for any HOD_Quenching_Model object.
| Parameters: | logM : array_like
halo_type : array
|
|---|---|
| Returns: | mean_quenched_fractions : array_like
|
Notes
The model assumes the quenched fraction is a polynomial in logM. The degree N quenching polynomial is determined by solving for the unique polynomial with values given by the central quenching ordinates at the logM abcissa. The coefficients of this polynomial are solved for by the solve_for_quenching_polynomial_coefficients method. This function assumes that these coefficients have already been solved for and bound to the input object as an attribute.