V2DL5 - High-level analysis for binary light curves for VERITAS

This is a collection of scripts for the high-level analysis of binary data for VERITAS. Focus is on the usage of gammapy and anasum for binary light curve analysis, meaning this is mostly a reflected region analysis with some binary specific tools.

Allows to run analysis scripts for a given list of runs or for a cone search around the given on_region direction.

• source detection analysis including integral flux (or flux upper limits), reflection region model
• spectral analysis, reflected region model
• run-list generation
• light-curve analysis and plotting

Installation

To install the required python packages, run:

bash conda env create -f environment.yml

Activate the environment to start the analysis:

bash conda activate v2dl5 pip install -e .

Analysis

Run list generator

The tool generate_run_list.py allows to generate a list of runs for a given observation time and zenith angle. It generates a lot of printout which should be used to fine tune the run selection.

Example:

console python v2dl5/scripts/generate_run_list.py \ --obs_table ../../../VTS/DL3/v490/dl3_pointlike_moderate2tel/obs-index.fits.gz \ --config examples/run_selection.yml \ --output_dir my_output_dir

Reflected region analysis

Reflected region analysis using gammapy:

console python v2dl5/scripts/reflected_region_analysis.py \ --run_list my_output_dir/runlist.txt \ --config examples/reflected_region.yml \ --output_dir my_output_dir

Binary light curve plotting

Light-curve plotting is independent of the analysis code. Input required is a table (ecsv format) with the light-curve data.

console python v2dl5/scripts/plot_binary_light_curves.py \ --instrument VERITAS \ --configuration examples/binary_lightcurve_plotting.yml

Auxiliary data

Auxiliary data is stored in v2dl5/data and available at runtime. This includes:

Star catalogues

Hippargos catalog for stars with magnitude < 9: v2dl5/data/hip_mag9.fits.gz. Star catalogs are listed in the configuration files as

yaml datasets: exclusion_region: on_radius: 0.5 deg magnitude_B: 7 star_exclusion_radius: 0.30 deg fov: 3.5 deg star_file: hip_mag9.fits.gz

Star catalogs are expected to be in the v2dl5/data directory and of FITS format.

Eventdisplay and anasum analysis

High-level analysis is also possible with the Eventdisplay package and its high-level tool anasum.

All scripts are containerized and can be run with the provided docker container.

Light-curve analysis

console ./light_curve_analysis.sh <anasum file> <time cuts file>

Use RUNWISE for the time cuts file to generate a light curve for each run.

Spectral analysis

console ./spectral_analysis.sh <anasum file> <output file>

Time cuts file

The time cuts file is a simple text file with the following format:

text MJD_start MJD_stop

To generate a time cuts file for nightly binning:

console ./nightly_time_bins.sh <anasum file>

Validate time cuts and generate run lists

Check that every run from the anasum file is inside one of the defined time cuts:

console ./runlist_from_time_bins.sh <anasum file> <time cuts file> false

Additionally write run lists for each of the MJD bins:

console ./runlist_from_time_bins.sh <anasum file> <time cuts file> true

The tool will also write a figure with the length-of-time bins vs time bin.

Acknowledgement

This work relies heavily on the gammapy development and especially on the excellent tutorials provided by the gammapy team.