The puzzling properties of the MACS1149-JD1 galaxy at z=9.11

Understand

We analyze new JWST NIRCam and NIRSpec data on the redshift 9.11 galaxy MACS1149-JD1.

• Our NIRCam imaging data reveal that JD1 comprises three spatially distinct components.
• Our spectroscopic data indicate that JD1 appears dust-free but is already enriched, $12 + \log {\rm (O/H) } = 7.90^{+0.04}_{-0.05}$.
• We also find that the Carbon and Neon abundances in JD1 are below the solar abundance ratio.