7–11 Jul 2025
Teaching and Learning Centre (TLC)
Europe/London timezone

Galaxy Zoo JWST: Up to 75% of discs are featureless at 3<z<7

Not scheduled
1h 30m
Teaching and Learning Centre (TLC)

Teaching and Learning Centre (TLC)

Durham University South Road Durham DH1 3LS
Poster Forging the elements: Understanding chemical evolution and stellar populations across cosmic time Forging the elements: Understanding chemical evolution and stellar populations across cosmic time

Description

We have not yet observed the epoch at which disc galaxies emerge in the Universe. While high-$z$ measurements of large-scale features such as bars and spiral arms trace the evolution of disc galaxies, such methods cannot directly quantify featureless discs in the early Universe. Here we identify a substantial population of apparently featureless disc galaxies in the Cosmic Evolution Early Release Science (CEERS) survey by combining quantitative visual morphologies of $\sim 7,000$ galaxies from the Galaxy Zoo JWST CEERS project with a public catalogue of expert visual and parametric morphologies. While the highest-redshift featured disc we identify is at $z_{\rm{phot}}=5.5$, the highest-redshift featureless disc we identify is at $z_{\rm{phot}}=7.4$. The distribution of S\'ersic indices for these featureless systems suggests that they truly are dynamically cold: disc-dominated systems have existed since at least $z\sim 7.4$. We place upper limits on the featureless disc fraction as a function of redshift, and show that up to $75\%$ of discs are featureless at $3.0

Primary author

Rebecca Smethurst (University of Oxford)

Co-authors

Prof. Brooke Simmons (University of Lancaster) Prof. Chris Lintott (University of Oxford) Dr Galaxy Zoo Team (Galaxy Zoo) Dr Hugh Dickinson (Open University) Dr Izzy Garland (Masaryk University) Mr Jason Makechemu (University of Lancaster) Mr Matthew Thorne (University of Lancaster) Ms Sophie Jewell (University of Oxford)

Presentation materials

There are no materials yet.