Description
The presence of a stellar bar in a disc galaxy indicates that the galaxy hosts, in its main part, a dynamically settled disc and that bar-driven processes are taking place in shaping its evolution. Therefore, studying the cosmic evolution of the bar fraction in disc galaxies is essential to understanding galaxy evolution. Using the HST, previous studies have found that the bar fraction significantly declines from the local Universe to redshifts near one. Using the JWST CEERS and the initial public observations for the PRIMER, this study extends the evolution of the bar fraction in disc galaxies to redshifts 1 ≤ 𝑧 ≤ 4, i.e., for the first time beyond redshift two. The results showed the JWST bar fraction to be twice the bar fraction found using bluer HST filters. The bar fraction is about 18% at 1 ≤ 𝑧 < 2, and about 14% at 2 ≤ 𝑧 < 3. Two barred galaxies are found at the highest redshift bin. I will discuss the impact of improved resolution and rest-frame wavelength on the bar fraction by repeating the study in both NIRCam filters F200W and F356W+F444W. Using longer wavelength filters, longer but rounder bars are observed, and bars are found to grow across this 5 Gyr range. These trends cannot be seen in the shorter wavelength filter F200W. These results already show that bar-driven evolution commences at early cosmic times and that dynamically settled discs are already present at a lookback time of ∼ 11 Gyrs.
