Mary, a pipeline to aid discovery of optical transients

TL;DR

The Mary pipeline is an automated tool designed to rapidly detect optical transients in high-cadence images, enabling quick follow-up for rare and fast astronomical events such as kilonovae and gamma-ray bursts.

Contribution

This paper introduces the Mary pipeline, a new automated system that efficiently detects optical transients with low false positive and missed rates during high-cadence observations.

Findings

False positive rate of ~2.2%

Missed fraction of ~3.4%

Detection time less than 2 minutes

Abstract

The ability to quickly detect transient sources in optical images and trigger multi-wavelength follow up is key for the discovery of fast transients. These include events rare and difficult to detect such as kilonovae, supernova shock breakout, and "orphan" Gamma-ray Burst afterglows. We present the Mary pipeline, a (mostly) automated tool to discover transients during high-cadenced observations with the Dark Energy Camera (DECam) at CTIO. The observations are part of the "Deeper Wider Faster" program, a multi-facility, multi-wavelength program designed to discover fast transients, including counterparts to Fast Radio Bursts and gravitational waves. Our tests of the Mary pipeline on DECam images return a false positive rate of ~2.2% and a missed fraction of ~3.4% obtained in less than 2 minutes, which proves the pipeline to be suitable for rapid and high-quality transient searches. The pipeline can be adapted to search for transients in data obtained with imagers other than DECam.