Finding New Debris Discs at Sub-millimetre Wavelengths

TL;DR

The paper addresses the incomplete census of debris discs by arguing for AtLAST, a wide-field, high-sensitivity submillimetre telescope that overcomes the confusion limit and captures extended emission. It outlines two concrete science cases—detecting faint nearby debris discs and tracing the birth of debris discs around Class III YSOs—with explicit performance benchmarks (e.g., $860 μm$ reach to ~21 μJy beam−1 within 10 pc and $350 μm$ resolution to ~1.7″ out to ~20 pc). It also specifies technical requirements (350–870 μm coverage, scale sensitivity up to 1′, <5″ resolution at <1 mm, and ≥1° FoV) and demonstrates how AtLAST could map star-forming regions within ~1 kpc in thousands of hours. Overall, AtLAST would enable unbiased, large-scale studies linking disc properties to planetary architectures, advancing our understanding of planetary system formation and evolution.

Abstract

Debris discs reveal the architectures and dynamical histories of planetary systems. Sub-millimetre observations trace large dust grains within debris discs, revealing their bulk properties. Debris discs have so far only been detected around ~20% of stars, representing the bright end of the population. A new facility is required to reach fainter discs, overcoming the confusion limit, with multiwavelength capabilities for characterisation, sensitivity to large-scale emission for nearby targets and a large field of view for surveying distant populations. All of this is made possible with the Atacama Large Aperture Submillimetre Telescope (AtLAST).

Figures (2)

• Figure 1:
• Figure 1: Fractional luminosity as a function of temperature for a simulated population of debris discs around nearby M dwarfs. The lines show approximate detection limits for Herschel/PACS and AtLAST.