hmf.mass_function.fitting_functions.Bhattacharya

class hmf.mass_function.fitting_functions.Bhattacharya(**kwargs)

Bhattacharya mass function fit.

For details on attributes, see documentation for FittingFunction.

Parameters

• nu2 (array_like) – A vector of peak-heights, \(\delta_c^2/\sigma^2\) corresponding to m

• m (array_like, optional) – A vector of halo masses [units M_sun/h]. Only necessary if req_mass is True. Typically provides limits of applicability. Must correspond to nu2.

• z (float, optional) – The redshift. Only required if req_z is True, in which case the default is 0.

• n_eff (array_like, optional) – The effective spectral index at m. Only required if req_neff is True.

• mass_definition (hmf.halos.mass_definitions.MassDefinition instance, optional) – A halo mass definition. Only required for fits which explicitly include a parameterization for halo definition.

• cosmo (astropy.cosmology.FLRW instance, optional) – A cosmology. Default is Planck15. Either omegam_z or cosmo is required if req_omz is True. If both are passed, omegam_z takes precedence.

• **model_parameters (unpacked-dictionary) – These parameters are model-specific. For any model, list the available parameters (and their defaults) using <model>._defaults

Notes

The Bhattacharya [1] form is:

\[f_{\rm Btc}(\sigma) = f_{\rm SMT}(\sigma) (\nu\sqrt{a})^{q-1}\]

References

1

Bhattacharya, S., et al., May 2011. ApJ 732 (2), 122. http://labs.adsabs.harvard.edu/ui/abs/2011ApJ…732..122B

Methods

__init__(**kwargs)	Initialize self.
get_measured_mdef()
get_models()	Get a dictionary of all implemented models for this component.
norm()

Attributes

cutmask	A logical mask array specifying which elements of fsigma are within the fitted range.
fsigma	Calculate \(f(\sigma)\) for Bhattacharya form.
lnsigma	Negative log of sigma.
nu	The peak height, sigma/delta_c.
omegam_z	Normalised matter density at current redshift.
req_mass	Whether m is required for this subclass
req_neff	Whether n_eff is required for this subclass
req_sigma
req_z
sigma	The sqrt of mass variance as a function of mass.
sim_definition	Details of the defining simulation, subclass of SimDetails