COSMOS-Web: Intrinsically Luminous z$\gtrsim$10 Galaxy Candidates Test Early Stellar Mass Assembly

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We report the discovery of 15 exceptionally luminous $10\lesssim z\lesssim14$ candidate galaxies discovered in the first 0.28 deg$^2$ of JWST/NIRCam imaging from the COSMOS-Web Survey.

• These sources span rest-frame UV magnitudes of $-20.5>M_{\rm UV}>-22$, and thus constitute the most intrinsically luminous $z\gtrsim10$ candidates identified by JWST to-date.
• Selected via NIRCam imaging with Hubble ACS/F814W, deep ground-based observations corroborate their detection and help significantly constrain their photometric redshifts.
• We analyze their spectral energy distributions using multiple open-source codes and evaluate the probability of low-redshift solutions; we conclude that 12/15 (80%) are likely genuine $z\gtrsim10$ sources and 3/15 (20%) likely low-redshift contaminants.