This paper presents the results of a search for high-redshift (z > 9) galaxy candidates in the JWST UNCOVER survey, utilizing deep NIRCam and NIRISS imaging across seven bands over ~45 arcmin². The identification of these candidates relies on dropout selection and photometric redshifts. The study finds 16 candidates at 9 < z < 12 and 3 candidates at 12 < z < 13, with eight considered very robust. These candidates exhibit a wide range of luminosities and young ages, low stellar masses, and low star formation rates, confirming previous findings. The analysis reveals evidence for a rapid redshift evolution of the mass-luminosity relation and a redshift evolution of the UV continuum slope, consistent with theoretical predictions. Deeper JWST observations and spectroscopic follow-up are deemed necessary to further investigate these early galaxies.

Hakim Atek, Iryna Chemerynska, Bingjie Wang, Lukas Furtak, Andrea Weibel, Pascal Oesch, John R Weaver, Ivo Labbé, Rachel Bezanson, Pieter Van Dokkum, Adi Zitrin, Pratika Dayal, Christina C Williams, Themiya Nannayakkara, Sedona H Price, Gabriel Brammer, Andy D Goulding, Joel Leja, Danilo Marchesini, Erica J Nelson, Richard Pan, Katherine E Whitaker