Impact of Chromatic Effects on LSST SNe Ia

The Supernova Atmospheric Simulation package (snat_sim) was developed within the Dark Energy Science Collaboration (DESC) to support research into the impact of atmospheric calibration techniques on astronomical observations of Type Ia Supernovae (SNe Ia). This documentation is provided as a technical reference for the package as well as minimal outline of the research it was designed to support. For questions concerning the snat_sim package, please see the API section of these docs or raise an issue on GitHub.


The snat_sim package is designed to support scientific research efforts. This documentation may at times assume the reader has a basic understanding of astronomy and how astronomical surveys work. However, these assumptions are kept to a minimum wherever possible.

Pipeline Overview

Each module of the snat_sim package is designed to represent a distinct stage of the analysis process. Ultimately, this functionality is brought together in the form of a single, modular analysis pipeline - the pipeline.FittingPipeline class.

An example of a running pipeline instance is shown below. Each process (colored in blue) is executed in parallel, and the number of processes launched in each pool (grey boxes) can be increased as necessary to meet performance requirements. Data sources read from or written to disk are shown in red. Objects cached in memory are shaded orange.


Light-Curve Simulation

The light-curve simulation process works by combining the results of several independent models. The intrinsic behavior of Type Ia Supernovae, the propagation of light through our atmosphere, and how the atmospheric makeup changes over time are all considered in the simulation.


Contribution and Usage

This project is open source and contributors are welcome. All involvement with this project, including source code contributions, is subject to the policies of the Dark Energy Science Collaboration, with particular emphasis on the Code of Conduct and Software Development Policy. More information is available here.