SEMINÁRIO DO DEPARTAMENTO DE ASTRONOMIA
Deciphering the origin of thick disks by their stellar populations
a talk by Francesca Pinna (Instituto de Astrofísica de Canarias) - In-Person
Abstract:
The evolutionary connection between thick and thin disks is still a matter of debate, while observations of high-redshift galaxies have recently shown that stellar disks of various thicknesses emerged very early in the universe. Their diversity seeded the large variety of properties observed in the local universe. Zooming into the spatially resolved stellar populations of very nearby galactic disks traces the story of spiral and lenticular galaxies, from the early stages to recent times. I will present my contribution on this topic, combining high-quality integral-field spectroscopy (IFS) observations of edge-on galaxies with high-resolution numerical simulations. Our recent studies have revealed different stellar populations of nearby thick disks in different types of galaxies, with different star-formation rates (SFRs), suggesting that they result from different evolution histories. The sharp transition, in earlier-type disk galaxies, between old, metal-poor and alpha-enhanced thick disks, and younger metal-rich thin disks, suggests that they formed in two distinct evolution phases. Highly star-forming late-type galaxies, with little differences between relatively young and metal-poor thick and thin disks, suggest a slower upside-down formation. I will finally compare these observations with AURIGA zoom-in cosmological simulations of Milky Way-mass galaxies, revealing one other piece of the puzzle: the connection between the fraction of in-situ and ex-situ stars and stellar-population properties. In these simulations, younger thick disks are explained by later and more massive mergers. These not only contribute younger stars from accreted satellite galaxies, but also large amounts of gas to extend off-plane star formation in time.
Short-Bio:
Francesca Pinna is a Marie Curie Fellow working in the field of Galaxy Evolution at the Instituto de Astrofísica de Canarias (IAC) in Tenerife (Spain). She leads her independent research in two different lines on the origin of stellar structures at galactic centers and large disk structures in external galaxies. She is an expert in the analysis of stellar kinematics and populations of internal structures in very nearby galaxies, mostly using (optical and infrared) integral-field spectroscopy (IFS) observations complemented by cosmological simulations. After a previous professional career in Industry as an engineer, she started her scientific career with a PhD at the IAC on the chemodynamical properties and origin of thick disks in galaxies. Then she moved as a postdoctoral researcher to the Max Planck Institute for Astronomy for four years, where she joined the Galactic Nuclei group and expanded her knowledge to the stellar kinematic and population properties of nuclear star clusters (NSCs). One year ago, she went back to the IAC to work on the spectrophotometric decomposition and stellar-population characterization of NSCs in the Phangs and BEARD survey. She has recently started the Marie Curie.
Google Meet: https://meet.google.com/pcw-gmem-jyi
Link da transmissão: https://www.youtube.com/c/AstronomiaIAGUSP/live