Résumé / Abstract Journal-club_Galaxies

Journal-club Galaxies

« Modeling and interpreting the spectral energy distribution of galaxies with BANGS »

Jacopo Chevallard
European Space Research Technology Center ESA (ESTEC) (Noordwijk, Pays-Bas)

Understanding the physical processes driving the formation and evolution of galaxies requires modeling their spectral energy distributions (SED). In this talk, I will present BANGS, a new general-framework tool for spectral analyses of galaxies. BANGS allows one to describe, in a flexible and physically consistent way, both the production of starlight in galaxies and its transfer through the interstellar and intergalactic media (ISM and IGM). It is therefore an ideal tool to produce realistic mock catalogues of galaxies as well as to interpret (spectro-photometric) observations. Currently, BANGS incorporates: a state-of-the-art population synthesis code; a photo-ionization model describing the emission from ionized gas; a model accounting for the effect of alpha-element variation on stellar emission; different prescriptions for dust attenuation; and several sets of star formation and chemical enrichment histories drawn from semi-analytic models and hydro-dynamic simulations. The code can deal with both photometric and spectroscopic data, and can accomplish three different, but closely related, tasks: create synthetic (i.e. "mock") catalogues of galaxy observables and compare the statistical properties of such catalogues with observations; create and fit synthetic observations to test our ability to retrieve input physical parameters; fit, with a Bayesian approach, galaxy observations to obtain statistical constraints on selected galaxy physical parameters. After a general overview of the code capabilities, I will present two applications of BANGS: to the determination of photometric redshifts of distant galaxies, and to the simulation of JWST-NIRSpec observations.
jeudi 24 septembre 2015 - 11:30
Salle 281, Institut d'Astrophysique
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