A formação de anãs castanhas é universal? Percepções do estudo dos enxames jovens mais massivos da Via Láctea.
Orador: Victor Abad
INAF, Osservatorio Astronomico di Palermo
Resumo:
Understanding the formation and evolution of young stars and clusters requires exploring a broad range of environments, from low-density star-forming regions to the most massive and extreme stellar nurseries in the Milky Way. As part of the EWOCS (Extended Westerlund 1 and 2 Open Clusters Survey) project, we have used JWST/NIRCam’s unprecedented sensitivity to study, for the first time, the substellar population in the supermassive clusters Westerlund 1 and 2. With total stellar masses exceeding 30,000 Msun, these clusters provide a unique laboratory to investigate how extreme conditions shape the low-mass end of the initial mass function. Theories predict that high stellar densities, and the presence of massive OB stars may alter brown dwarf formation efficiency, but this remains untested in massive young clusters. In this talk, I will present our JWST/NIRCam findings, including the detection and characterization of brown dwarfs straddling the planetary-mass regime in Westerlund 2, and the (sub)stellar initial mass function of Westerlund 1. By placing these results in context with studies of other massive young clusters, we establish the first systematic constraints on brown dwarf demographics in massive environments. Our results offer new perspectives on the role of the environment in shaping the low-mass end of the initial mass function and provide essential benchmarks for future studies of young clusters across the Milky Way.
Entidade organizadora: Instituto de Astrofísica e Ciências do Espaço/U.Lisboa
Data e hora: 06 fevereiro 2026, 13:30
Local: C8.2.02, Faculdade de Ciências da Universidade de Lisboa