Sorcha: A Solar System Survey Simulator for the Legacy Survey of Space and Time

Abstract

The upcoming Legacy Survey of Space and Time(LSST)at the Vera C. Rubin Observatory is expected torevolutionize solar system astronomy. Unprecedented in scale, this 10 yr wide-field survey will collect billions ofobservations and discover a predicted similar to 5 million new solar system objects. Like all astronomical surveys, itsresults will be affected by a complex system of intertwined detection biases. Survey simulators have long beenused to forward-model the effects of these biases on a given population, allowing for a direct comparison to realdiscoveries. However, the scale and tremendous scope of the LSST requires the development of new tools. In thispaper we presentSorcha, an open-source survey simulator written inPython. Designed with the scale ofLSST in mind,Sorchais a comprehensive survey simulator to cover all solar system small-body populations. Itsflexible, modular design allowsSorchato be easily adapted to other surveys by the user. The simulator is builtto run both locally and on high-performance computing clusters, allowing for repeated simulation of millions tobillions of objects(both real and synthetic).