FLEET: A Redshift-Agnostic Machine Learning Pipeline to Rapidly Identify Hydrogen-Poor Superluminous Supernovae

TL;DR

This paper introduces FLEET, a machine learning pipeline that rapidly identifies hydrogen-poor superluminous supernovae without needing redshift information, enabling efficient follow-up observations.

Contribution

The paper presents a novel, redshift-agnostic machine learning classifier for SLSN-I, improving rapid identification and purity in transient surveys.

Findings

Achieves 85% purity with 20% completeness in SLSN-I classification.

Can identify about 20 candidates per year currently, increasing to over 1000 with future surveys.

Provides alternative classifiers with higher purity and completeness using redshift or full light curves.

Abstract

Over the past decade wide-field optical time-domain surveys have increased the discovery rate of transients to the point that $\lesssim 10\%$ are being spectroscopically classified. Despite this, these surveys have enabled the discovery of new and rare types of transients, most notably the class of hydrogen-poor superluminous supernovae (SLSN-I), with about 150 events confirmed to date. Here we present a machine-learning classification algorithm targeted at rapid identification of a pure sample of SLSN-I to enable spectroscopic and multi-wavelength follow-up. This algorithm is part of the FLEET (Finding Luminous and Exotic Extragalactic Transients) observational strategy. It utilizes both light curve and contextual information, but without the need for a redshift, to assign each newly-discovered transient a probability of being a SLSN-I. This classifier can achieve a maximum purity of about 85\% (with 20\% completeness) when observing a selection of SLSN-I candidates. Additionally, we present two alternative classifiers that use either redshifts or complete light curves and can achieve an even higher purity and completeness. At the current discovery rate, the FLEET algorithm can provide about $20$ SLSN-I candidates per year for spectroscopic follow-up with 85\% purity; with the Legacy Survey of Space and Time we anticipate this will rise to more than $\sim 10^3$ events per year.