SNIascore: Deep Learning Classification of Low-Resolution Supernova Spectra

Abstract

We present SNIascore, a deep-learning based method for spectroscopic classification of thermonuclear supernovae (SNe Ia) based on very low-resolution (R $\sim 100$) data. The goal of SNIascore is fully automated classification of SNe Ia with a very low false-positive rate (FPR) so that human intervention can be greatly reduced in large-scale SN classification efforts, such as that undertaken by the public Zwicky Transient Facility (ZTF) Bright Transient Survey (BTS). We utilize a recurrent neural network (RNN) architecture with a combination of bidirectional long short-term memory and gated recurrent unit layers. SNIascore achieves a $<0.6\%$ FPR while classifying up to $90\%$ of the low-resolution SN Ia spectra obtained by the BTS. SNIascore simultaneously performs binary classification and predicts the redshifts of secure SNe Ia via regression (with a typical uncertainty of $<0.005$ in the range from $z=0.01$ to $z=0.12$). For the magnitude-limited ZTF BTS survey ($\approx 70\%$ SNe Ia), deploying SNIascore reduces the amount of spectra in need of human classification or confirmation by $\approx 60\%$. Furthermore, SNIascore allows SN Ia classifications to be automatically announced in real-time to the public immediately following a finished observation during the night.

12 pages, 5 figures, 2 tables, accepted for publication in ApJL

References in corpus (10)

• The Zwicky Transient Facility: System Overview, Performance, and First Results
• The Zwicky Transient Facility: Data Processing, Products, and Archive
• The Zwicky Transient Facility: Science Objectives
• The Zwicky Transient Facility: Surveys and Scheduler
• The Zwicky Transient Facility: Observing System
• Optical Spectra of 73 Stripped-Envelope Core-Collapse Supernovae
• Type II supernova spectral diversity I: Observations, sample characterization and spectral line evolution
• The GROWTH Marshal: A Dynamic Science Portal for Time-Domain Astronomy
• A Fully Automated Integral Field Spectrograph Pipeline for the SEDMachine: pysedm
• Towards An Integrated Optical Transient Utility

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