Theoretical vs semi-empirical stellar population models: a controlled experiment

• Grant number: 17/02375-2
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• Start date: July 03, 2017
• End date: August 02, 2017
• Field of knowledge: Physical Sciences and Mathematics - Astronomy - Extragalactic Astrophysics
• Principal Investigator: Paula Rodrigues Teixeira Coelho
• Grantee: Paula Rodrigues Teixeira Coelho
• Visiting researcher: Gustavo Ramon Bruzual Alfonzo
• Visiting researcher institution: Universidad Nacional Autónoma de México, Morelia (UNAM), Mexico
• Host Institution: Instituto de Astronomia, Geofísica e Ciências Atmosféricas (IAG). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Stellar population synthesis (SPS) models are invaluable to modern Extragalactic Astrophysics. They provide means to extract stellar masses, mean stellar ages, star formation histories, chemical enrichment histories and dust content of galaxies from their integrated spectral energy distributions, colours or spectra. But a common concern when using these models to interpret observations is that "they do not come with error bars". In other words, we do not fully understand the accuracy and precision to which our current models can be trusted. One source of uncertainty which has not been properly studied yet regards the impact of using an empirical stellar flux library versus a theoretical stellar library to build the SPS models. In this proposed one-month long visit to IAG/USP, we will perform experiments to compare how the qualities and caveats of empirical versus theoretical libraries of stellar spectra impact the integrated properties of SPS models. In particular, it will be possible to answer the following questions: (1) How the uncertainties already identified in theoretical stellar libraries will affect integrated colours and spectral indices of model stellar populations? (2) How will the non-uniform coverage of the HR diagram by empirical libraries impact in the predicted integrated properties of stellar populations? and (3) How random errors in the atmospheric parameters will translate into the SSP models?Moreover, in parallel to the research activities, a colloquium on Stellar Population Modelling will be given at the department, and discussion activities will be offered to the students of the Astronomy graduate program. Such activities will provide the students with the opportunity to learn methods and concepts about this important field in Extragalactic Astrophysics. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

COELHO, PAULA R. T.; BRUZUAL, GUSTAVO; CHARLOT, STEPHANE. To use or not to use synthetic stellar spectra in population synthesis models?. Monthly Notices of the Royal Astronomical Society, v. 491, n. 2, p. 2025-2042, JAN 2020. (18/05392-8, 17/02375-2)

RODRIGUEZ-MERINO, LINO H.; MAYYA, Y. D.; COELHO, PAULA R. T.; BRUZUAL, GUSTAVO; CHARLOT, STEPHANE; CARRASCO, ESPERANZA; DE PAZ, ARMANDO GIL. High-resolution Spectral Line Indices Useful for the Analysis of Stellar Populations. Astrophysical Journal Letters, v. 889, n. 2, FEB 1 2020. (18/05392-8, 17/02375-2)

BONOLI, S.; MARIN-FRANCH, A.; VARELA, J.; VAZQUEZ RAMIO, H.; ABRAMO, L. R.; CENARRO, A. J.; DUPKE, R. A.; VILCHEZ, J. M.; CRISTOBAL-HORNILLOS, D.; GONZALEZ DELGADO, R. M.; et al. The miniJPAS survey: A preview of the Universe in 56 colors. Astronomy & Astrophysics, v. 653, SEP 3 2021. (18/05392-8, 11/18729-1, 15/11442-0, 17/02375-2)