COSI GRB Group Simulations

This repository contains the code and inputs for COSI GRB simulations, as well as other short-duration transients which will need to be classified and investigated by the GRB group. This is a work in progress; please open an issue if you notice any problems/mistakes or missing features, and contact Eliza ([email protected]) with any questions.

Steps to Running Simulations

1. Create source input files, either using data observed by other telescopes (e.g. Fermi-GBM) or theoretical models. download_gbm_data.py is an example script that can be used to download lightcurves and spectra from Fermi-GBM. These files should be uploaded here. gbm_to_megalib.py may be used to convert the downloaded lightcurves and spectra to the formats required to generate the MEGAlib .source files. These files should be uploaded here.
2. Generate MEGAlib .source files for transient events. source_file_generation.py may be used to generate these files. They should be uploaded here.
3. Simulate the .source files using cosima, reconstruct the resulting .sim files using revan, and perform event selections on the resulting .tra files using mimrec. run_cosima.py, run_revan.py, and run_mimrec.py are example scripts that can be used to run cosima, revan, and mimrec, respectively. For onboard trigger algorithm simulations or anti-coincidence shield (BGO) only simulations, only the cosima step is necessary. The MEGAlib simulations should be uploaded here.
4. Combine source simulations with background simulations. Depending on the analysis, this may be done at either the .sim or .tra file level. There are MEGAlib tools (e.g. mtraconcatter) which do this (see the MEGAlib documentation), and trigger_algorithm_list_generation.py can be used to create input files for the onboard trigger algorithm.

Directories

• example_scripts/ contains scripts that can be used to download Fermi-GBM spectra and lightcurves, bin the lightcurves using Bayesian blocks and convert the spectra and lightcurves into MEGAlib input files, create MEGAlib .source files, run simulations in MEGAlib, and create input files for the onboard trigger algorithm. See the README file in example_scripts/ for more details.
• grb_simulator/ contains the code used for the scripts in example_scripts/.

Simulation Files

• The information needed to download the GBM data used to create the MEGAlib input files can be found here.
• MEGAlib input files (information needed to generate simulation sets) can be found here. For use with source_file_generation.py, spectral files must be in the form event-name_spectrum.dat or event-name_spectrum.yaml and lightcurves must be in the form event-name_lightcurve.dat. Examples of spectral and lightcurve .yaml files can be found in example_yaml_files/, and information about the spectral .dat file format can be found in the MEGAlib documentation.
• MEGAlib source files (outputs of sample_source_file_generation.py) can be found here.
• Source simulations of GRBs and other transients (outputs of run_cosima.py, run_revan.py, and run_mimrec.py) can be found here, and background simulations can be found here.
• Event list files used to test the onboard trigger algorithm (outputs of trigger_algorithm_list_generation.py) can be found here.