CCToolkit is a Python package designed for Cluster Cosmology calculations. It handles cosmological parameters, power spectrum computations, halo mass functions, and halo bias and integrates with the CAMB library to deliver precise cosmological data processing.
- Cosmological Calculations: Easily compute various cosmological quantities, including background quantities and power spectra.
- Halo Mass Function (HMF): Implements the multiplicity function and HMF parameters for different halo finders based on the model presented in Castro et al. 2023 or the model presented in Castro et al. 2025 for dynamical dark energy cosmologies.
- Halo Bias: Implements the functions to compute the linear halo bias, with corrections based on the Peak Background Split (PBS) model presented in Castro et al. 2024b.
- Baryonic impact: Implements the model presented in Castro et al. 2024a for the baryonic impact on cluster and group masses.
- Utility Functions: Provides useful utilities for manipulating the power spectrum.
To install CCToolkit clone the repository and use pip:
git clone https://github.com/TiagoBsCastro/CCToolkit.git
cd CCToolkit
python -m pip install .- Python 3.9+
- NumPy
- SciPy
- CAMB
To use CCToolkit, start by importing the necessary modules and initializing the CosmologyCalculator with your desired cosmological parameters:
from cctoolkit import CosmologyCalculator
# Define cosmological parameters
params = {
'H0': 70.0, # Hubble parameter at z=0 in km/s/Mpc
'Ob0': 0.05, # Baryon density parameter
'Om0': 0.3, # Total matter density parameter (Ob0 + Om_c0)
'sigma8': 0.8, # rms density fluctuation amplitude at 8 h^-1 Mpc
'ns': 0.96, # Scalar spectral index
'TCMB': 2.7255, # CMB Temperature at z=0 in K
'mnu': 0.06, # Sum of neutrino masses (eV)
'num_massive_neutrinos': 1 # Number of massive neutrinos species
}
# Initialize the calculator
cosmo_calc = CosmologyCalculator(params)Calculate the halo mass function for a range of masses following Castro et al. 2023:
import numpy as np
import matplotlib.pyplot as plt
masses = np.logspace(13, 15.5, num=100)
hmf = cosmo_calc.dndlnM(masses, 0)
plt.loglog(masses, hmf)
plt.xlabel(r"$M_{\rm vir}\,[M_\odot h^{-1}]$")
plt.ylabel(r"$\frac{{\rm d} n}{{\rm d} \log M}\,[{\rm Mpc}^{-3} h^{3}]$")
plt.show()Alternatively, using following the model Castro et al. 2025 for dynamical dark energy:
import numpy as np
import matplotlib.pyplot as plt
masses = np.logspace(13, 15.5, num=100)
hmf = cosmo_calc.dndlnM(masses, 0, model='castro25')
plt.loglog(masses, hmf)
plt.xlabel(r"$M_{\rm vir}\,[M_\odot h^{-1}]$")
plt.ylabel(r"$\frac{{\rm d} n}{{\rm d} \log M}\,[{\rm Mpc}^{-3} h^{3}]$")
plt.show()CCToolkit can compute both the PBS prescription as well as the corrected model following Castro et al. 2024b.
pbs = cosmo_calc.pbs_bias(masses, 0)
bias = cosmo_calc.bias(masses, 0)
plt.loglog(masses, pbs, label=r'${\rm PBS}$')
plt.loglog(masses, bias, label=r'${\rm Castro\, et\,al.\,2024}$')
plt.xlabel(r"$M_{\rm vir}\,[M_\odot h^{-1}]$")
plt.ylabel(r"$b(M)$")
plt.legend()
plt.show()CCToolkit can compute the equivalent dark-matter-only halo mass of a hydrodynamical simulated group or cluster in two simple steps following the model of Castro et al. 2024a:
import cctoolkit
from cctoolkit import baryons
from cctoolkit.cosmology import CosmologyCalculator
z = 0.0
# Magneticum cosmology
params = {"Om0": 0.272, "Ob0": 0.272 * 0.168, "H0": 70.4, "ns": 0.963, "mnu":0, "num_massive_neutrinos": 0, "sigma8": 0.809}
cosmo_calc = CosmologyCalculator()
# Array of virial masses on hydro
M = np.geomspace(1e13, 3e14)
# Calculating the equivalent DMO mass at the threshold of equivalence according to the quasi-adiabatic model
M_Delta_dmo, Delta = baryons.compute_dmo_mass(M, z, 0.168)
Delta *= cctoolkit.utils.virial_Delta(cosmo_calc.Omega_m(z))
# Converting to the virial mass
mdmo = [baryons.compute_rec_mass(cosmo_calc, m, d, z) for m, d in zip(M_Delta_dmo, Delta)]Please visit CCToolkit Documentation for detailed documentation and API reference.
Contributions are welcome! Please see our Contributing Guidelines for details on how to contribute to this project. You can report issues, suggest features, or submit pull requests.
This project is licensed under the MIT License. See the LICENSE file for more information.
This package relies on the CAMB library for cosmological calculations. We also acknowledge the authors of the various halo finder software used to produce the best-fit parameters implemented in this package.