def HaloConcentration(mass, cosmo, redshift, mdef='vir'):
"""
Return halo concentration from halo mass, based on the analytic fitting
formulas presented in
`Dutton and Maccio 2014 <https://arxiv.org/abs/1402.7073>`_.
.. note::
The units of the input mass are assumed to be :math:`M_{\odot}/h`
Parameters
----------
mass : array_like
either a numpy or dask array specifying the halo mass; units
assumed to be :math:`M_{\odot}/h`
cosmo : :class:`~nbodykit.cosmology.cosmology.Cosmology`
the cosmology instance used in the analytic formula
redshift : float
compute the c(M) relation at this redshift
mdef : str, optional
string specifying the halo mass definition to use; should be
'vir' or 'XXXc' or 'XXXm' where 'XXX' is an int specifying the
overdensity
Returns
-------
concen : :class:`dask.array.Array`
a dask array holding the analytic concentration values
References
----------
Dutton and Maccio, "Cold dark matter haloes in the Planck era: evolution
of structural parameters for Einasto and NFW profiles", 2014, arxiv:1402.7073
"""
from halotools.empirical_models import NFWProfile
if not isinstance(mass, da.Array):
mass = da.from_array(mass, chunks=100000)
# initialize the model
kws = {'cosmology':cosmo.to_astropy(), 'conc_mass_model':'dutton_maccio14', 'mdef':mdef, 'redshift':redshift}
model = NFWProfile(**kws)
return mass.map_blocks(lambda mass: model.conc_NFWmodel(prim_haloprop=mass), dtype=mass.dtype)
def get_nfw_conc(mass, redshift):
kw1 = {}
kw1.update(kws)
kw1['redshift'] = redshift
model = NFWProfile(**kw1)
return model.conc_NFWmodel(prim_haloprop=mass)
def get_nfw_conc(mass, redshift):
kw1 = {}
kw1.update(kws)
kw1['redshift'] = redshift
model = NFWProfile(**kw1)
return model.conc_NFWmodel(prim_haloprop=mass)