Dark Matter Halos (skypy.halo
)¶
This module contains methods that model the properties of dark matter halo populations.
You can reproduce figure 2 in Sheth and Tormen 1999 and plot the collapse functions for different halo models. For this, you can use a python script, for example.
import numpy as np
from astropy.cosmology import Planck15
from skypy.power_spectrum import eisenstein_hu
from skypy.halo.mass import _sigma_squared
# Power spectrum and amplitude of perturbations at redshift 0
growth_0 = 1.0
A_s, n_s = 2.1982e-09, 0.969453
k = np.logspace(-3, 1, num=1000, base=10.0)
mass = 10**np.arange(9.0, 15.0, 0.1)
pk0 = eisenstein_hu(k, A_s, n_s, Planck15, kwmap=0.02, wiggle=True)
sigma = np.sqrt(_sigma_squared(mass, k, pk0, growth_0, Planck15))
# Collapse functions
from skypy.halo import mass
params_ellipsoidal = (0.3, 0.7, 0.3, 1.686)
ST = mass.sheth_tormen_collapse_function(sigma)
PS = mass.press_schechter_collapse_function(sigma)
EM = mass.ellipsoidal_collapse_function(sigma, params=params_ellipsoidal)
You can also sample halos using their mass function. For this, you can use a config file and run the pipeline, for example.
cosmology: !astropy.cosmology.default_cosmology.get
power_spectrum: !skypy.power_spectrum.eisenstein_hu
wavenumber: !numpy.logspace [-3, 1, 100]
A_s: 2.1982e-09
n_s: 0.969453
cosmology: $cosmology
sheth-tormen: !skypy.halo.mass.sheth_tormen
m_min: 1.0E+10
m_max: 1.0E+13
resolution: 10000
wavenumber: !numpy.logspace [-3, 1, 100]
power_spectrum: $power_spectrum
growth_function: 1.0
cosmology: $cosmology
size: 10000
press-schechter: !skypy.halo.mass.press_schechter
m_min: 1.0E+10
m_max: 1.0E+13
resolution: 10000
wavenumber: !numpy.logspace [-3, 1, 100]
power_spectrum: $power_spectrum
growth_function: 1.0
cosmology: $cosmology
size: 10000
Abundance Matching (skypy.halo.abundance_matching
)¶
Abundance matching module.
This module provides methods to perform abundance matching between catalogs of galaxies and dark matter halos.
Models¶
Vale & Ostriker abundance matching. |
Mass (skypy.halo.mass
)¶
Halo mass sampler. This code samples halos from their mass function.
Models¶
Ellipsoidal collapse function. |
|
Halo mass function. |
|
Halo mass sampler. |
|
Number of subhalos. |
|
Halo mass sampler. |
|
Ellipsoidal collapse function. |
|
Halo mass function. |
|
Halo mass sampler. |
|
Ellipsoidal collapse function. |
|
Halo mass function. |
|
Subhalo mass sampler. |
Quenching (skypy.halo.quenching
)¶
Galaxy quenching.
This module implements models for environment and mass quenching by dark matter halos.
Models¶
Environment quenching function. |
|
Mass quenching function. |