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

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., $A_{\rm V}\sim1\,{\rm mag}$). These "red spiral" galaxies would be interesting, potentially new population of galaxies, as we start to see their detailed morphology using JWST, for the first time. Finally, we note that the spectral energy distribution of these red $z\sim2.5$ galaxies could mimic $z>10$ Lyman break galaxies and contaminate to $z>10$ galaxy samples, especially when they were faint and small.