04–08 mag 2026
L'Aquila
Europe/Rome fuso orario

The unexpected stellar populations of the Milky Way's satellite Fornax dSph

4 mag 2026, 15:15
15m

Relatore

Dall'Ora, Massimo (Istituto Nazionale di Astrofisica (INAF))

Descrizione

Building upon the seminal work of Searle & Zinn (1978) and within the framework of the Λ-CDM paradigm, the Milky Way (MW) halo is understood to have formed through the progressive and ongoing accretion of smaller sub-galactic fragments. This hierarchical assembly can be empirically tested via Near-Field Cosmology, specifically by comparing theoretical structural predictions with star-by-star observations of extant MW satellites.

Among these satellites, the Fornax dwarf Spheroidal (dSph) is particularly significant; its substantial mass allows it to host its own system of globular clusters and complex, multi-modal stellar populations. While Fornax is known for its diverse metallicity and age distributions, it presents a striking anomaly for a dSph: an intermediate-age population (~1.5 Gyr) and a potential young component (~200 Myr). Recent KiDS (Kilo-Degree Survey) catalogues derived from VST imaging further suggest an even younger stellar population of approximately 100 Myr. To validate this, we have initiated an observational campaign to identify these extremely young stars and characterize their associated variable star populations, providing a definitive temporal record of Fornax's recent star-formation history.

Sessione La Galassia e il Gruppo Locale

autore

Dall'Ora, Massimo (Istituto Nazionale di Astrofisica (INAF))

Coautore

Bono, Giuseppe Dr. Braga, Vittorio Fiorentino, Giuliana (Istituto Nazionale di Astrofisica (INAF)) Gatto, Massimiliano (Istituto Nazionale di Astrofisica (INAF)) Gholami, Mahtab (Istituto Nazionale di Astrofisica (INAF)) Jones, Miriya (Florida State University) Dr. Marconi, Marcella (Istituto Nazionale di Astrofisica (INAF)) Marengo, Massimo (Florida State University) Dr. Monelli, Matteo (INAF - Osservatorio d'Abruzzo) Ragusa, Rossella (Istituto Nazionale di Astrofisica (INAF)) Tortora, Crescenzo (Istituto Nazionale di Astrofisica (INAF))

Materiali di presentazione

Non sono ancora presenti materiali