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arXiv · 2207.09436

Early results from GLASS-JWST. III: Galaxy candidates at z$\sim$9-15

Marco Castellano·Adriano Fontana·Tommaso Treu·Paola Santini·Emiliano Merlin·Nicha Leethochawalit·Michele Trenti·Uros Mestric·Eros Vanzella·Andrea Bonchi·Davide Belfiori·Mario Nonino·Diego Paris·Gianluca Polenta·Guido Roberts-Borsani·Kristan Boyett·Marusa Bradac·Antonello Calabro·Karl Glazebrook·Claudio Grillo·Sara Mascia·Charlotte Mason·Amata Mercurio·Takahiro Morishita·Themiya Nanayakkara·Laura Pentericci·Piero Rosati·Benedetta Vulcani·Xin Wang·Lilan Yang
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Abstract

We present the results of a first search for galaxy candidates at z$\sim$9--15 on deep seven-bands NIRCam imaging acquired as part of the GLASS-JWST Early Release Science Program on a flanking field of the Frontier Fields cluster A2744. Candidates are selected via two different renditions of the Lyman-break technique, isolating objects at z$\sim$9-11, and z$\sim$9-15, respectively, supplemented by photometric redshifts obtained with two independent codes. We find five color-selected candidates at z$>$9, plus one additional candidate with photometric redshift z$_{phot}\geq$9. In particular, we identify two bright candidates at $M_{UV}\simeq -21$ that are unambiguously placed at $z\simeq 10.6$ and $z\simeq 12.2$, respectively. The total number of galaxies discovered at $z>9$ is in line with the predictions of a non-evolving LF. The two bright ones at $z>10$ are unexpected given the survey volume, although cosmic variance and small number statistics limits general conclusions. This first search demonstrates the unique power of JWST to discover galaxies at the high redshift frontier. The candidates are ideal targets for spectroscopic follow-up in Cycle$-2$.

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Marco Castellano, Adriano Fontana, Tommaso Treu, Paola Santini, Emiliano Merlin, Nicha Leethochawalit, Michele Trenti, Uros Mestric, Eros Vanzella, Andrea Bonchi, Davide Belfiori, Mario Nonino, Diego Paris, Gianluca Polenta, Guido Roberts-Borsani, Kristan Boyett, Marusa Bradac, Antonello Calabro, Karl Glazebrook, Claudio Grillo, Sara Mascia, Charlotte Mason, Amata Mercurio, Takahiro Morishita, Themiya Nanayakkara, Laura Pentericci, Piero Rosati, Benedetta Vulcani, Xin Wang, Lilan Yang. 2022-07-19. Early results from GLASS-JWST. III: Galaxy candidates at z$\sim$9-15. https://doi.org/10.3847/2041-8213%2Fac94d0

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