Speaker
Description
The James Webb Space Telescope’s incomparably sensitive InfraRed coverage detects rest-frame optical light from UV-faint galaxies falling beyond Hubble’s detection limits. Such previously-unseen Hubble-Dark galaxies challenge our galaxy formation, evolution and chemical enrichment models, constraining theories for structure formation and mass buildup in the early Universe. We use the JWST/MINERVA survey to characterise the largest-yet HST-Dark sample in the literature. We select 372 HST-Dark sources using multi-band MINERVA photometry, model their spectra statistically using BAGPIPES, perform a non-parametric morphological analysis and study their distribution in the physical parameter space. Applying completeness limits (z > 2), the 325 selected galaxies have median $z\sim4.15$, stellar mass $M_*\sim10^{9.64} M_{\odot}$, star-formation rate (SFR)$\sim22.45 M_{\odot}/yr$, and dust attenuation $A_V\sim 1.85$. They demonstrate a ~30% previously-missed contribution to the redshift-binned, dust-unobscured, integrated cosmic SFR density (CSFRD) at $z\sim 7–8$. Consistently smaller sizes across all stellar-mass bins indicate higher baryonic density than HST-bright counterparts. Our complete HST-Dark population thus reveals hitherto-unstudied, high-mass, extremely-dusty, moderately star-forming sources at high-z, with non-negligible contribution to early-Universe cosmological parameters like the evolving CSFRD.
| Nature of work | Computational |
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