Red Spiral Galaxies in the Cosmic Noon Unveiled in the First JWST Image

Understand

In the first image of the James Webb Space Telescope (JWST) of SMACS J0723.3-7327, one of the most outstanding features is the emergence of a large number of red spiral galaxies, because such red spiral galaxies are only a few percent in the number fraction among nearby spiral galaxies.

• While these apparently red galaxies were already detected with the Spitzer Space Telescope at $\sim3-4{\rm \mu m}$, the revolutionized view from JWST's unprecedented spatial resolution has unveiled their hidden spiral morphology for the first time.
• Within the red spiral galaxies, we focus on the three most highly red galaxies that are very faint in the $<0.9\,{\rm \mu m}$ bands and show red colors in the $2-4\,{\rm \mu m}$ bands.
• Our study finds that the three extremely red spiral galaxies are likely to be in the Cosmic Noon (i.e., $1 < z < 3$) and could be consistent with passive (i.e., $\sim$ zero star-formation rates) galaxies having moderate dust reddening (i.e., $A_{\rm V}\sim1\,{\rm mag}$).