The Physical Properties of Galaxies in the First 700 Million Years as Revealed by JWST
Sofia Rojas (University of California, Los Angeles)
Thursday 28/05/2026 @ 11:30, Sala Antonio Sollima (IV piano Battiferro)
In the first three years since operation, JWST has presented new puzzles on the formation of the first galaxies in the universe. We unexpectedly found galaxies truly bright in ultraviolet light as early as in the first ~300 Myrs of the history of the Universe, commonly referred to as “blue monsters”. I will present the latest results on the physical characteristics of galaxies within the first 700 Myr, as studied with the 'Brightest of Reionizing Galaxies (BoRG-JWST) survey'. This unique spectroscopic campaign uses NIRSpec to follow up HST-selected galaxies in this cosmic epoch across >300 independent sight lines, minimizing cosmic variance and providing a robust view of the bright galaxy population in early times. I will present results demonstrating that the BoRG-JWST galaxies exhibit properties akin to the earlier “blue monsters” and investigate their star formation histories, dust content, and potential signatures of active galactic nuclei.