SEMINÁRIO DO DEPARTAMENTO DE ASTRONOMIA
Galaxy Evolution from z = 2.4 to 0.2: Morphology, Star Formation, and the Rise of Spheroids
a talk by Vitor Medeiros Sampaio (Universidade Técnica Federico Santa Maria) - In-Person
Abstract:
In this talk, I’ll present results from a comprehensive study of how galaxy morphology and star formation evolve over cosmic time, focusing on a sample of around 14,000 galaxies from the CANDELS survey, spanning redshifts from 2.4 down to 0.2. To classify galaxies, we developed a hybrid unsupervised-supervised method based on non-parametric morphological indices, carefully tailored for narrow redshift bins to capture evolutionary trends and minimize observational biases. I’ll show how relying on a single classification model across broad redshift ranges can lead to significant errors—especially in estimating the fraction of disk galaxies. By combining our morphological analysis with star formation indicators, we find that disk-dominated galaxies maintain high specific star formation rates while slowly decreasing in stellar mass, whereas spheroids tend to grow more massive and eventually quench, likely through mergers involving massive disks. These results support a downsizing picture of galaxy evolution and offer fresh insights into galaxy populations during cosmic noon. I’ll also share some preliminary findings from JWST data that point toward exciting directions for future work.
Short-Bio:
I hold a Bachelor's degree in Physics from UNICAMP, a Master's degree from INPE, and a PhD from the Universidade Cidade de São Paulo (UNICID). During my PhD, I spent one year at the University of Nottingham as part of a doctoral stay, under the supervision of Professors Dr. Alfonso Aragón Salamanca and Dr. Michael R. Merrifield. I completed my PhD in February of this year and have since been working as a postdoctoral researcher at the Universidad Técnica Federico Santa María, in Valparaíso (Chile), under the supervision of Dr. Yara Jaffé, in direct collaboration with the CHANCES survey.
Google Meet: https://meet.google.com/pcw-gmem-jyi
Link da transmissão: https://www.youtube.com/c/AstronomiaIAGUSP/live