The supernova Ia progenitor problem in the 2040s

TL;DR

The paper discusses the challenge of identifying and characterizing Type Ia supernova progenitors by the 2040s, emphasizing the need for advanced observational techniques and instrumentation to improve understanding of their origins.

Contribution

Proposes a modular, multi-aperture telescope array with fast, low-noise spectrographs to enable continuous, high-resolution spectroscopy of diverse SN Ia progenitor candidates.

Findings

Upcoming surveys will identify thousands of potential progenitors.

High-time-resolution spectroscopy is essential for accurate characterization.

A novel telescope array design can meet observational challenges.

Abstract

Type Ia supernovae (SNe Ia) are fundamental to cosmology and galactic chemical evolution, yet the nature of their progenitor systems remains unresolved. Multiple evolutionary pathways, including single-degenerate, double-degenerate, and helium-donor systems, are thought to contribute to the SN Ia population, but direct observational constraints are limited. This uncertainty hampers our understanding of SN Ia diversity and introduces systematic uncertainties in their use as precision cosmological probes. By the 2040s, surveys such as Gaia, LSST, SDSS-V, 4MOST, and the gravitational-wave mission LISA will identify thousands of compact binaries in the Milky Way that are potential SN Ia progenitors. However, survey discoveries alone are insufficient. Robust identification and characterization require high-time-resolution, phase-resolved spectroscopy to determine fundamental parameters such as component masses, orbital inclinations, chemical compositions, and accretion states. Addressing these challenges demands new observational capabilities. The most compact binaries require continuous, dead-time-free spectroscopy with negligible readout noise, while the progenitor population spans a wide range of brightness and orbital periods. A modular, multi-aperture telescope array equipped with fast, low-noise spectrographs can flexibly combine collecting area for faint targets, observe bright systems efficiently, and deliver uninterrupted time series through staggered exposures. Such observations are difficult for single-aperture facilities.