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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

To use or not to use synthetic stellar spectra in population synthesis models?

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Author(s):
Coelho, Paula R. T. [1] ; Bruzual, Gustavo [2] ; Charlot, Stephane [3]
Total Authors: 3
Affiliation:
[1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Rua Matao 1226, BR-05508090 Sao Paulo - Brazil
[2] UNAM, Inst Radioastron & Astrofis, Campus Morelia, Morelia 58089, Michoacan - Mexico
[3] Sorbonne Univ, CNRS, UMR7095, Inst Astrophys Paris, F-75014 Paris - France
Total Affiliations: 3
Document type: Journal article
Source: Monthly Notices of the Royal Astronomical Society; v. 491, n. 2, p. 2025-2042, JAN 2020.
Web of Science Citations: 0
Abstract

Stellar population synthesis (SPS) models are invaluable to study star clusters and galaxies. They provide means to extract stellar masses, stellar ages, star formation histories, chemical enrichment, and dust content of galaxies from their integrated spectral energy distributions, colours, or spectra. As most models, they contain uncertainties that can hamper our ability to model and interpret observed spectra. This work aims at studying a specific source of model uncertainty: the choice of an empirical versus a synthetic stellar spectral library. Empirical libraries suffer from limited coverage of parameter space, while synthetic libraries suffer from modelling inaccuracies. Given our current inability to have both ideal stellar-parameter coverage with ideal stellar spectra, what should one favour: better coverage of the parameters (synthetic library) or better spectra on a star-by-star basis (empirical library)? To study this question, we build a synthetic stellar library mimicking the coverage of an empirical library, and SPS models with different choices of stellar library tailored to these investigations. Through the comparison of model predictions and the spectral fitting of a sample of nearby galaxies, we learned that predicted colours are more affected by the coverage effect than the choice of a synthetic versus empirical library; the effects on predicted spectral indices are multiple and defy simple conclusions; derived galaxy ages are virtually unaffected by the choice of the library, but are underestimated when SPS models with limited parameter coverage are used; metallicities are robust against limited HRD coverage, but are underestimated when using synthetic libraries. (AU)

FAPESP's process: 18/05392-8 - A new library of fully theoretical stellar population models
Grantee:Paula Rodrigues Teixeira Coelho
Support Opportunities: Regular Research Grants
FAPESP's process: 17/02375-2 - Theoretical vs semi-empirical stellar population models: a controlled experiment
Grantee:Paula Rodrigues Teixeira Coelho
Support Opportunities: Research Grants - Visiting Researcher Grant - International