Repository overview

This repository contains the code implemented and used in:

A halo model approach to describe clustering and emission of the two main star-forming galaxy populations for Cosmic Infrared Background studies, G. Zagatti, E. Calabrese, C. Chiocchetta, M. Gerbino, M. Negrello, L. Pagano

Installation

Instructions on how to install and set up the project.

git clone https://github.com/giorgiazagatti/CIB_halomodel.git
cd CIB_halomodel

How to use

This repository contains three parameter files correspondent to the three datasets employed in the study. The user can create his own parameter file using the same structure (and detailed below). Once the parameter file is set and selected in the module theory_CIB.py, the latter will provide the CIB power spectrum in a file.txt with dimension (n,m) where n is the number of frequency auto- and cross-spectra, and m is the number of multipoles in the analysis. The parameter file has to be selected in the first block of the theory_CIB.py module:

#----------------------------------------------------------------------------------------------------------------------------
#----------------------------------open and read the paramfile, different options available----------------------------------
#----------------------------------------------------------------------------------------------------------------------------
#with open("paramfile_SPIRE.yaml") as f:
#with open("paramfile_Lenz.yaml") as f:
with open("paramfile_Planck.yaml") as f:
    settings = yaml.load(f, Loader=SafeLoader)

Once everything is set, to obtain the CIB power spectrum just run:

%run theory_CIB.py

Examples about the visualization of the results are provided in this repository.

Parameters description

In this repository, there are three parameter files that mimic the datasets used in the study. The structure of the parameter files is the same and it is composed of three main blocks:

• Options: to set up the general settings
• Frequencies: instrumental features of the specific experiment
• Parameters: cosmological parameters, model parameters, power spectra parameters

In the following we provide for a description of each block of the parameter file.

Options

In this first block of the parameter file, the user can modify how to deal with the matter power spectrum, the different normalization of the power spectra, the multipole range in which the user wants to compute the CIB power spectra and the redshift.

• Linear matter power spectrum. The user can choose between three different options:
  • Use the tabulated matter power spectrum employed in the study. This has been computed with CAMB, using the Planck18 cosmology. To choose this option, set:

    read_matterPS: True

  • Compute the matter power spectrum for a different cosmology. To compute it, the user has to change the previous flag:

    read_matterPS: False

    and the linear matter power spectrum is computed by the code with CAMB.
  • Use a linear matter power spectrum provided by the user. In this case, the user has to set the flag at True, and insert the path to his matter power spectrum in the third block of the parameter file, and specifically, in the label 'matter_PS':

    parameters:
      cosmology:
        T_CMB: 2.725
        tau: 0.0544
        ns: 0.9649
        As: 2.101e-9
        pivot_scalar: 0.05
        matter_PS: 

• Power spectra normalization. Flag to choose between CIB power spectra computed in $C_\ell$'s or in $D_\ell$'s. In particular, if

  normalization: 0 

  the resulting power spectra are computed in $C_\ell$'s, otherwise, if

  normalization: 1 

  the CIB power spectra are computed in $D_\ell$'s.
• Multipole range: to set the minimum and the maximum multipoles to compute the CIB power spectra.

  ell_range:          #set the minimum and the maximum ell for the CIB power spectra computation
    ell_min: 1
    ell_max: 2000 

  Default values are set for the different datasets.
• Redshift: path to the redshifts for the analysis.

Frequencies

The second block contains the information related to each experiment. Specifically:

• the frequency channels of the experiment/dataset;
• the units of the CIB power spectra of the dataset. The default option is $Jy^2$ for all the parameter files, however it is also possible to compute the power spectra in $\mu K^2$ changing:

    units: 'Jy^2'

  in:

    units: 'muK^2'

• the effective frequency for the CIB emission;
• the color corrections for each frequency channel.

Parameters

The third block allows the user to act on both the cosmological parameters and the ones of the model and it is divided into four sub-blocks.

• Cosmological paramters: if the user wants to compute the linear matter power spectrum using CAMB and a different cosmology or, if the user wants to use his own linear matter power spectrum, he has to modify these parameters or provide for the path to his linear matter power spectrum.
• Fixed parameters: paramters used for the computation of the CIB power spectrum.
• Clustering parameters: paramters of the halo occupation distribution for early- and late-type galaxies.
• Power spectra parameters: calibration factors, correlation coefficients and shot noise levels for the different frequency channels.