Foreground Simulation for 21 cm Reionization Signal Detection

The fg21sim is a low-frequency radio foregrounds simulator aiming to provide the simulation of the common foregrounds impeding the 21 cm reionization signal detection.

The simulated foregrounds can be used to evaluate the impacts of different foreground components on the EoR signal, and can be also used to help develop and test various foreground removal methods.

Status

We are working on the next-gen simulation suite Fg21Sim+ , which offers higher resolution, better fidelity, and, eventually, a full sky coverage for all the foreground components. Future updates will be added to the next-gen suite.

Demo Papers

Here are papers using the fg21sim to simulate the foregrounds:

• Lian,+ 2020: Contribution of Galactic free-free emission to the foreground for EoR signal in SKA experiments;
• Li,+ 2019: Contribution of Radio Halos to the Foreground for SKA EoR Experiments;
• Li,+ 2019: Separating the EoR signal with a convolutional denoising autoencoder: a deep-learning-based method;

Features

• Supported foreground components:
  • galactic/synchrotron: Galactic synchrotron emission (Note: only the unpolarized part considered)
  • galactic/freefree: Galactic free-free emission
  • galactic/snr: Emission from Galactic supernovae remnants (SNRs)
  • extragalactic/clusters: Emission from extragalactic galaxy clusters (Note: only giant radio halos, the modeling of which is elaborated in our paper: 2019, ApJ, 879, 104; ADS:2019ApJ...879..104L; arXiv:1905.05399)
• High-resolution simulation within sky patches
• Fine-grained control with various configuration options
• Modular and extensible
• Clean code
• Command line utilities

Installation

1. Install the required software and libraries:

   • CFITSIO
   • HEALPix: only the C++ library required by healpy.
   • LLVM: (required by llvmlite that is further required by Numba)

2. Clone this repository:

   $ git clone https://github.com/Fg21Sim/fg21sim
   

3. Install the required third-party Python packages. And it is recommended to use the virtual environment:

   $ cd fg21sim/
   $ make venv
   $ . venv/bin/activate
   (venv) $
   

   Check to make sure that this virtual environment is activated so that the python3 and pip3 are pointed to the virtual environment.

4. Install this software into the virtual environment:

   (venv) $ python3 setup.py install
   

5. You are ready to use this software. Just have a look, e.g.:

   (venv) $ fg21sim --help
   

Development

To ease the development, install this package in the editable state:

$ cd fg21sim/
$ pip3 install --user -r requirements.txt
$ pip3 install --editable .

In addition, setting the environment variable DEBUG_FG21SIM forces this software to run at the DEBUG logging level.

Documentations

To get started, read the User Guide. See also this simulation example.

License

Unless otherwise declared:

• Codes developed by us are distributed under the MIT License;
• Documentations and products generated by us are distributed under the Creative Commons Attribution 3.0 License;
• Third-party codes and products used are distributed under their own licenses. See also LICENSE-3RDPARTY.