No Dyson Swarm Signatures Detected in 129 Galaxies; Upper Limits Reach 0.3% Median Covering Fraction
This preprint delivers the most rigorous SPS-based null result yet for galaxy-scale waste heat, calibrated by injection tests and buttressed by new archival screens. It shifts SETI strategy toward resolved outskirts of quiescent galaxies and future FIR photometry. The work underscores that color selection alone cannot separate technosignatures from starbursts or AGN.
The team embedded the AGENT waste-heat formalism inside Flexible Stellar Population Synthesis so that nebular and dust emission responded self-consistently to reprocessing. They ran 1,419 injection-recovery tests across spectral types, recovering injected covering fractions with slope m=0.92 and detecting signals down to 4-5% in quiescent systems. None of the 129 galaxies preferred a Dyson component, converting to a population limit of less than 2.6% of galaxies hosting 25% swarms at 95% confidence.
Curtis et al.: PRIMA FIR photometry of 20 quiescent galaxy outskirts will either detect or exclude α=5% swarms at 3σ within 18 months of first light.
Sources (2)
- [1]Primary Source(https://arxiv.org/abs/2608.12458)
- [2]Supporting Source(https://ui.adsabs.harvard.edu/abs/2023ApJ...945...35W)