A UV-to-IR view of a nearby high-z analog with JWST and HST to interpret the first galaxies
Matilde Mingozzi (STScI, Baltimora)
Tuesday 24/06/2025 @ 14:00, Sala Antonio Sollima (IV piano Battiferro)
In the current JWST era, detailed observations of the first generation of galaxies have started to revolutionize our knowledge of the early Universe, with outstanding but also puzzling discoveries. In particular, high-z systems in the epoch of reionization (z>6) are generally found to be low-mass, compact and metal-poor, and show prominent emission lines, indicating extreme radiation fields. However, their properties are not trivial to be determined, some seem to show intriguing chemical inhomogeneities and an unprecedented number of them may host massive accreting black holes (i.e., Active Galactic Nucleus, AGN, activity) already in the first billion years. Nearby blue compact dwarf galaxies such as SBS 0335-052 E share similar properties, and thus represent the perfect local laboratories for the multi-wavelength detailed studies required to understand the properties and mechanisms driving such intriguing scenarios. In this talk, I will show new MIRI/MRS data of SBS 0335-052 E, mapping MIR lines (e.g., [NeII], [SIV], [NeIII], [OIV], [NeV]), in combination with UV spectroscopy and imaging. These data map the ionized gas at different level of ionization and dust attenuation at sub-kpc scales in this system for the first time. Thus, they allow us to investigate the main ionization sources of the gas (massive stars, shocks or AGN) in this high-z analog, revealing the presence of an extended very high ionization emission possibly due to an accreting intermediate massive black hole. Overall, this study provides us with an extremely powerful toolkit, pivotal for understanding the gas conditions and feedback from different ionization sources in the earliest galaxies that reionized the universe.