Lunch talk on Oct. 19, 2022

Multicomponent models of the interstellar medium in low-metallicity dwarf galaxies

Speaker: Lise Ramambason (CEA)

Venue: Video Conference

Time: 12:30 PM, Wednesday, Oct. 19, 2022

Abstract: 

I will present a new modeling framework MULTIGRIS (Lebouteiller & Ramambason 2022) based on Bayesian statistics, which is well-adapted to study the multiphase interstellar medium (ISM), including and especially within low-metallicity galaxies. In such chemically unevolved environments, important changes of the gas heating and cooling mechanisms are expected, with an impact on the resulting spectral signatures. We intend to use those spectral signatures as probes of the physical conditions in low-metallicity dwarf galaxies, which may resemble the conditions expected in the early universe. In particular, we can infer quantities such as the escape fraction of ionizing photons from HII regions or the gas mass distribution in different ISM phases, including the so-called « CO-dark » phase. Tools like MULTIGRIS may help gain insights into the complex mechanisms at play in the first galaxies that formed within the Reionization epoch and open promising opportunities for future applications, including for high-redshift galaxies, with the already available and future detections from ALMA and JWST.