The propagation of uncertainties in stellar population synthesis modeling III: model calibration, comparison, and evaluation - Astrophysics > Cosmology and Nongalactic AstrophysicsReport as inadecuate




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Abstract: Stellar population synthesis SPS provides the link between the stellar anddust content of galaxies and their observed spectral energy distributions. Inthe present work we perform a comprehensive calibration of our own flexible SPSFSPS model against a suite of data. Several public SPS models areintercompared, including the models of Bruzual and Charlot BC03, Maraston M05and FSPS. The relative strengths and weaknesses of these models are evaluated,with the following conclusions: 1 The FSPS and BC03 models compare favorablywith MC data at all ages, whereas M05 colors are too red and the age-dependenceis incorrect; 2 All models yield similar optical and near-IR colors for oldmetal-poor systems, and yet they all provide poor fits to the integrated J-Kand V-K colors of both MW and M31 star clusters; 4 All models predict ugrcolors too red, D4000 strengths too strong and Hdelta strengths too weakcompared to massive red sequence galaxies, under the assumption that suchgalaxies are composed solely of old metal-rich stars; 5 FSPS and, to a lesserextent, BC03 can reproduce the optical and near-IR colors of post-starburstgalaxies, while M05 cannot. Reasons for these discrepancies are explored. Thefailure at predicting the ugr colors, D4000, and Hdelta strengths can beexplained by some combination of a minority population of metal-poor stars,young stars, blue straggler and-or blue horizontal branch stars, but not byappealing to inadequacies in either theoretical stellar atmospheres orcanonical evolutionary phases e.g., the main sequence turn-off. We emphasizethat due to a lack of calibrating star cluster data in regions of themetallicity-age plane relevant for galaxies, all of these models continue tosuffer from serious uncertainties that are difficult to quantify. ABRIDGED



Author: Charlie Conroy, James E. Gunn

Source: https://arxiv.org/







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