velociraptor.fitting_formulae.smhmr module

Fitting formulae for the stellar mass-halo mass relation.

velociraptor.fitting_formulae.smhmr.moster(catalogue: velociraptor.catalogue.catalogue.Catalogue, mass_range: Union[unyt.array.unyt_array, List[unyt.array.unyt_quantity]] = [unyt_quantity(10000., 'Msun'), unyt_quantity(1.e+16, 'Msun')], n_eval: int = 256)

The moster retaion (from Moster+ 2013). Original code provided by Matthieu Schaller. Takes:

• catalogue, your catalogue object

• mass_range, a length 2 array with the lowest and highest halo mass

  you would like the relation to be evaluated between (default: 1e4 msun to 1e16 msun)

• n_eval, the number of function evaluations (equally spaced in log (Mhalo))

  (default: 256)

Returns:

• halo_mass, the halo masses at which the relation is evaluated at
• stellar_mass, the stellar masses matching with the above halo masses

velociraptor.fitting_formulae.smhmr.moster_raw(z, Mhalo)

Stellar mass-halo mass relation from Moster+2013.

Provided by Matthieu Schaller.

velociraptor.fitting_formulae.smhmr.behroozi(catalogue: velociraptor.catalogue.catalogue.Catalogue, mass_range: Union[unyt.array.unyt_array, List[unyt.array.unyt_quantity]] = [unyt_quantity(10000., 'Msun'), unyt_quantity(1.e+16, 'Msun')], n_eval: int = 256)

The behroozi fit to the SMHMR (from Behroozi+ 2013). Original code provided by Matthieu Schaller. Takes:

• catalogue, your catalogue object

• mass_range, a length 2 array with the lowest and highest halo mass

  you would like the relation to be evaluated between (default: 1e4 msun to 1e16 msun)

• n_eval, the number of function evaluations (equally spaced in log (Mhalo))

  (default: 256)

Returns:

• halo_mass, the halo masses at which the relation is evaluated at
• stellar_mass, the stellar masses matching with the above halo masses

velociraptor.fitting_formulae.smhmr.behroozi_raw(z, Mhalo)

Stellar mass-halo mass relation from Behroozi +2013.

Provided by Matthieu Schaller.

velociraptor.fitting_formulae.smhmr.behroozi_2019_raw(z, Mhalo)

Stellar mass-halo mass relation from Behroozi +2019.

The data is taken from https://www.peterbehroozi.com/data.html

This function is a median fit to the raw data for centrals (i.e. excluding satellites)

The stellar mass is the true stellar mass (i.e. w/o observational corrections)

The fitting function does not include the intrahalo light contribution to the stellar mass

The halo mass is the peak halo mass that follows the Bryan & Norman (1998) spherical overdensity definition

Provided by Evgenii Chaikin.