skypy.halos.colossus_mf

skypy.halos.colossus_mf(redshift, model, mdef, m_min, m_max, sky_area, cosmology, sigma8, ns, resolution=1000, noise=True)

Sample halo redshifts and masses from a COLOSSUS mass function.

Sample the redshifts and masses of dark matter halos following a mass function implemented in COLOSSUS [1] within given mass and redshift ranges and for a given area of the sky.

Parameters:

redshiftarray_like

Defines the edges of a set of redshift bins for which the mass function is evaluated. Must be a monotonically-increasing one-dimensional array of values. Halo redshifts are sampled between the minimum and maximum values in this array.

modelstring

Mass function model which is available in colossus.

mdefstr

Halo mass definition for spherical overdensities used by colossus.

m_min, m_maxfloat

Lower and upper bounds for the halo mass in units of Solar mass, Msun.

sky_areaQuantity

Sky area over which halos are sampled. Must be in units of solid angle.

cosmologyCosmology

Cosmology object to calculate comoving densities.

sigma8float

Cosmology parameter, amplitude of the (linear) power spectrum on the scale of 8 Mpc/h.

nsfloat

Cosmology parameter, spectral index of scalar perturbation power spectrum.

noisebool, optional

Poisson-sample the number of halos. Default is True.

Returns:

redshift, masstuple of array_like

Redshifts and masses of the halo sample.

References

[1]

Diemer B., 2018, ApJS, 239, 35