2025ApJ...995L..74B

We present measurements of stellar population properties of a newly discovered, spectroscopically confirmed, $z=11.1{0}_{-0.26}^{+0.11}$, gravitationally lensed galaxy, using JWST NIRSpec PRISM spectroscopy and NIRCam imaging. The arc is highly magnified by the Bullet Cluster (magnification factor $\mu =14.{0}_{-0.3}^{+6.2}$). It contains three star-forming components of which one is barely resolved and two are unresolved, giving intrinsic sizes of ≲10 pc. The clumps also contain ∼50% of the total stellar mass. The galaxy formed the majority of its stars ∼150 Myr ago (by z ∼ 14). The spectrum shows a pronounced damping wing, typical for galaxies deep in the reionization era and indicating a neutral intergalactic medium at this line of sight. The intrinsic luminosity of the galaxy is $0.08{6}_{-0.030}^{+0.008}\,{L}^{* }$ (with L^* being the characteristic luminosity for this redshift), making it the lowest-luminosity spectroscopically confirmed galaxy at z > 10 discovered to date.