Joint Astrophysical Colloquium
New insights into extreme star-forming galaxies: testing and calibrating new-generation spectral models for the JWST era
Jacopo Chevallard (IAP Paris)
Thursday 04/04/2019 @ 11:30, Sala IV piano Battiferro
Current observations favour a Cosmic Reionization scenario in which young stars hosted in low-mass galaxies produce the bulk of ionizing photons necessary to reionize the Intergalactic Medium (IGM) by z~6. This scenario, however, rests on several assumptions about the physical properties of high-redshift galaxies and their interstellar medium (ISM). The James Webb Space Telescope (JWST), scheduled for launch in March 2021, will provide the observational capabilities necessary to precisely characterise the properties of galaxies and of the ISM out to the Reionization Epoch. Extracting physical insights from the unique JWST data, however, will require the use of adequate interpretive tools, which must be tested and calibrated using existing facilities. In this talk, I will present the results of modelling HST/COS spectra of local “analogues” of low-mass high-redshift galaxies. By using the spectral modelling tool Beagle, along with state-of-the-art stellar population and photoionization models, I will show how the diverse UV and optical spectral features of these galaxies can be reproduced with a full self-consistent physical model. I will highlight the successes and failures of current generation of models, and discuss the future model developments required to maximise the science extracted from deep JWST spectra.