echo21 4.0.0

Exploring the Cosmos with Hydrogen Observation

Overview

Name:

Exploring Cosmos with Hydrogen Observation

Author:

Shikhar Mittal

Paper:

Mittal et al (2026)

Documentation:

echo21.readthedocs.io

Why do you need this code?

Use this code to generate the global 21-cm signal(s) for a given set of astrophysical and cosmological parameters.

Read more about it in the paper Mittal et al (2026).

Installation and requirements

This package can be installed as

pip install echo21

We recommend working on a Python version > 3.8. Packages required are

• numpy (recommended version 2.1.3)

• scipy (recommended version 1.14.1)

• mpi4py (recommended version 4.0.1)

• tqdm (recommended version 4.67.1)

• colossus (recommended version 1.3.6)

• pybaselines (recommended version 1.1.0)

• pandas (recommended version 3.0.1)

Quick start

The following code more or less captures the main functionalities of this package.

from echo21 import echopipeline

pipe = echopipeline.pipeline()
pipe.run_simulation()

Save the above code as (say) my_echo_script.py and run it as

python my_echo_script.py

Running the above will generate an output folder with the name output_<YYYYMMDD-hhmmss> which contains several files. To learn how to set the astrophysical or cosmological parameters, halo mass function, star formation model, redshifts at which to evaluate the global signal, and structure of the output files see the documentation. To learn about the physics of this package see our paper.

Once you have an understanding of the structure of output files, you can write your own scripts to create figures. To help you get started, see the jupyter notebook make_figures.ipynb in the example folder.

Documentation

For more details on the working of the package and understanding the output files refer to the documentation.

License and citation

The software is free to use on the MIT open-source license. If you use the software then please cite Mittal et al (2026).

If the code is used in a project where the author has provided significant scientific input, guidance on methodology, or assistance with interpretation of results, then co-authorship on resulting publications is expected, following standard academic practice.

Users are encouraged to contact the author when using the code for new scientific applications or major projects.