When the Universe Turned Dark: Tracing Cosmic Dust from the Big Bang to Present Day

by Dr Tom Bakx (CTH)

Friday 5 Dec 2025, 10:30 → 11:30 Europe/Stockholm

FC61 (AlbaNova Main Building)

Roughly half of all starlight ever emitted has been absorbed by interstellar dust and re-radiated at far-infrared wavelengths, fundamentally shaping our view of galaxy evolution. Even at 600 million years after the Big Bang, galaxies harbour warm dust reservoirs rivaling the brightest local systems. Yet despite the high stellar masses revealed by JWST (implying millions of dust-producing supernovae), deep ALMA observations detect no dust emission, highlighting our uncertainties in the emergence, evolution and impact of dust across the past 13.8 billion years.

I will present an overview of our best constraints on early obscured galaxy evolution. Using ALMA Bands 1 through 10 efficiently, I detail our best picture on resolved dust, gas and star formation maps in 200 dusty star-forming galaxies, revealing the diversity of extreme star formation modes. Furthermore, I systematically investigate their larger environments through a novel machine learning framework, exploring the dust-selected protocluster candidates from substantial archival datasets (>2000 hours) combined with ongoing spectroscopic programs. Extending dust studies to younger galaxies, I will present a picture of dust formation and emission properties from composite ALMA imaging out to the pre-reionization Universe, concluding with recommendations for next-generation facilities (AtLAST, ALMA2040).