Search and characterization of satellite galaxies and stellar streams

• Grant number: 22/10833-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: September 01, 2022
• End date: July 31, 2023
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Stellar Astrophysics
• Principal Investigator: Claudia Lucia Mendes de Oliveira
• Grantee: Pierre Augusto Ré Martho
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 11/51680-6 - Exploring the universe: from the galaxies formation to Earth-like planets with the Giant Magellan Telescope, AP.ESP

Abstract

Multi-band surveys such as the Southern photometric Local Universe survey (Mendes de Oliveira et al. 2019) have a key advantage: the narrow band that covers the magnesium triplet (filter J0515) is sensitive to the surface gravity of stars, which allows the selection of distant giant stars (e.g. Majewski et al., 2000). Cleaning the sample of nearby dwarf stars is crucial, as they can correspond to more than 90% of the stars in the magnitude range observed. This filtering process allows us to highlight distant overdensities, even though this survey does not reach magnitudes as faint as others (e.g. DES, SDSS). In previous studies, we have developed a method to highlight stars of a given stellar population in the SDSS survey (which has been used to successfully find a stellar stream in the Pegasus region; Perottoni et al., 2019). As part of another undergrad research project, this method was adapted to the SPLUS survey and is now ready to be applied in large-scale surveys. This capacity to highlight distant populations of giant stars will be used to search for new stellar overdensities in the form of satellite galaxies, as well as to map the structure of known stellar streams, and select candidate stars for spectroscopic follow-ups to study their chemical abundances, which is important for us to better understand their origins and the role that they play in the chemodynamical evolution of the Milky Way Galaxy. (AU)