Beasts in the Bubbles: Remarkably UV-bright Galaxies at z=9-10
VLT/XSHOOTER | 25.7hrs | PI - S. Fuijimoto
We propose X-shooter observations for four UV-bright (H=24.5-25.4 mag) novel candidates at z=9-10 from the brand new COSMOS2020 catalogue, now benefitting from homogeneous near-IR and ultra-deep optical coverage. All candidates have clear Lyman-break features, IRAC detection, tight distributions in PDF(z) at z=9-10, the inconsistency with any stellar templates and lower-z galaxy, and are confirmed at z>9 with four independent redshift estimates. The volume density of these four candidates is also consistent with the bright-end of the latest UV luminosity function (UVLF) studies at z=9-10. We will 1) confirm the redshift and the power-law nature of the UVLF at z=9-10; and test if UV-bright galaxies at z=9-10 2) reside in ionized bubbles; and 3) host AGN via the Nv1243 line. Our targets will provide essential constraints on the bright/massive-end of luminosity/mass function at z>9 and the CDM scenario for the formation of early galaxies, once at least one is confirmed.