A Young Supernova Selection Pipeline For The LSST Era

Abstract

Early-time spectroscopy of supernovae (SNe), acquired within days of explosion, yields crucial insights into their outermost ejecta layers, facilitating the study of their environments, progenitor systems, and explosion mechanisms. Recent efforts in early discovery and follow-up of SNe have shown the potential insights that can be gained from early-time spectra. Surveys such as the Time-Domain Extragalactic Survey (TiDES), conducted with the 4-meter Multi-Object Spectroscopic Telescope (4MOST), will provide spectroscopic follow-up of transients discovered by the Legacy Survey of Space and Time (LSST). Current simulations indicate that early-time spectroscopic studies conducted with TiDES data will be limited by the current SN selection criteria. To enhance early-time SN spectroscopic studies from TiDES-like surveys, we propose a set of selection criteria focusing on young SNe (YSNe), which we define as SNe prior to -10 days before peak brightness. Utilising the Zwicky Transient Facility transient alerts, we developed criteria to select YSNe while minimising the sample's contamination rate to 23 percent. The developed criteria were applied to LSST simulations, yielding a sample of 694 Deep Drilling Field survey SNe and 56,260 Wide Fast Deep survey SNe for follow-up. We demonstrate that our criteria enables the selection of SNe at early-times, enhancing future early-time spectroscopic SN studies from TiDES-like surveys. Finally, we investigated 4MOST-like observing strategies to increase the sample of spectroscopically observed YSNe. We propose that a 4MOST-like observing strategy that follows LSST with a delay of 3 days is optimal for a TiDES-like SN survey in terms of the number of classifiable spectra obtained, while a 1 day delay is most optimal for enhancing the early-time science in conjunction with our YSN selection criteria.

Accepted for publication in MNRAS (December 2025)

References in corpus (60)

• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• LSST: from Science Drivers to Reference Design and Anticipated Data Products
• Correcting for the Effects of Interstellar Extinction
• The Zwicky Transient Facility: System Overview, Performance, and First Results
• The Zwicky Transient Facility: Data Processing, Products, and Archive
• X-shooter, the new wide band intermediate resolution spectrograph at the ESO Very Large Telescope
• SN 2006gy: Discovery of the most luminous supernova ever recorded, powered by the death of an extremely massive star like Eta Carinae
• Three-dimensional delayed-detonation models with nucleosynthesis for Type Ia supernovae
• Double-detonation sub-Chandrasekhar supernovae: can minimum helium shell masses detonate the core?
• A giant outburst two years before the core-collapse of a massive star
• Seeing the Collision of a Supernova with its Companion Star
• Confined Dense Circumstellar Material Surrounding a Regular Type II Supernova: The Unique Flash-Spectroscopy Event of SN 2013fs
• A Wolf-Rayet-like progenitor of supernova SN 2013cu from spectral observations of a wind
• SNANA: A Public Software Package for Supernova Analysis
• Three-dimensional pure deflagration models with nucleosynthesis and synthetic observables for Type Ia supernovae
• Double-detonation sub-Chandrasekhar supernovae: synthetic observables for minimum helium shell mass models
• Head-on collisions of white dwarfs in triple systems could explain type Ia supernova
• Three-Dimensional Delayed-Detonation Model of Type Ia Supernova
• The Risetime of Nearby Type Ia Supernovae
• Double-detonation supernovae of sub-Chandrasekhar mass white dwarfs
• Flash Spectroscopy: Emission Lines from the Ionized Circumstellar Material around $<10$-Day-Old Type II Supernovae
• The SED Machine: a robotic spectrograph for fast transient classification
• 3D deflagration simulations leaving bound remnants: a model for 2002cx-like Type Ia supernovae
• Simulations of the WFIRST Supernova Survey and Forecasts of Cosmological Constraints
• Observational Predictions for Sub-Chandrasekhar Mass Explosions: Further Evidence for Multiple Progenitor Systems for Type Ia Supernovae
• Failed-Detonation Supernovae: Sub-Luminous Low-Velocity Ia Supernovae and Their Kicked Remnant White Dwarfs with Iron-Rich Cores
• The Rise-Time Distribution of Nearby Type Ia Supernovae
• A Fully Automated Integral Field Spectrograph Pipeline for the SEDMachine: pysedm
• The Initiation and Propagation of Helium Detonations in White Dwarf Envelopes
• Models and Simulations for the Photometric LSST Astronomical Time Series Classification Challenge (PLAsTiCC)
• The Zwicky Transient Facility Alert Distribution System
• Spin-Up/Spin-Down models for Type Ia Supernovae
• SN 2005bf: A Possible Transition Event Between Type Ib/c Supernovae and Gamma Ray Bursts
• Delayed detonations in full-star models of Type Ia supernova explosions
• The Rising Light Curves of Type Ia Supernovae
• The Rise and Fall of Type Ia Supernova Light Curves in the SDSS-II Supernova Survey
• Exploring the Potential Diversity of Early Type Ia Supernova Light Curves
• The prevalence and influence of circumstellar material around hydrogen-rich supernova progenitors
• Early light curves for Type Ia supernova explosion models
• Constraining Type Ia Supernovae progenitors from three years of SNLS data
• ZTF Early Observations of Type Ia Supernovae II: First Light, the Initial Rise, and Time to Reach Maximum Brightness
• Spectrophotometric templates for core collapse supernovae and their application in simulations of time-domain surveys
• The ESO/VLT 3rd year Type Ia supernova data set from the Supernova Legacy Survey
• The Physics of Flash (Supernova) Spectroscopy
• Early emission from type Ia supernovae
• Constraining Type Ia supernova explosions and early flux excesses with the Zwicky Transient Factory
• An Early-Time Optical and Ultraviolet Excess in the type-Ic SN 2020oi
• The new SOXS instrument for the ESO NTT
• Exploring the diversity of double detonation explosions for type Ia supernovae: Effects of the post-explosion helium shell composition
• The circumstellar material around the Type IIP SN 2021yja
• The core-degenerate scenario for the progenitors of type Ia supernovae
• Limits on a population of collisional-triples as progenitors of Type-Ia supernovae
• Characterizing the Rapid Hydrogen Disappearance in SN2022crv: Evidence of a Continuum between Type Ib and IIb Supernova Properties
• Recovered SN Ia rate from simulated LSST images
• Early Lightcurves of Type Ia Supernovae are Consistent with Nondegenerate Progenitor Companions
• Type Ia Supernovae Can Arise from the Detonations of Both Stars in a Double Degenerate Binary
• Companion Shocking Fits to the 2018 ZTF Sample of SNe Ia Are Consistent with Single-Degenerate Progenitor Systems