Résumé / Abstract Journal-club_Galaxies

Journal-club Galaxies

« X-ray spectra of hot circum-galactic medium around spiral galaxies: connecting simulations to observations »

Aditi Viyajan
Indian Inst. Astroph., Koramangala (Bangalore, Inde)

Star formation in galaxies drives outflows of hot gas into the circumgalactic medium (CGM). The hot component of such outflows is detected as diffuse extra-planar X-ray emission using instruments such as Chandra and XMM-Newton. The X-ray spectra help constrain the temperature of this plasma, which gives important information for the feedback model. When interpreting the current spectra, simplified assumptions are being made, such as 1-T or 2-T model, with a uniform metallicity. The actual condition of the extra-planar gas can be much more complicated, because of the interaction between outflows and halo gas. We have conducted 3-D hydrodynamic simulations of disk galaxies, using an accurate feedback model adopted from high-resolution, small-box simulations. We analyze the physical properties of galaxy corona, which show a broad distribution of density, temperature and metallicity. We use Pyxsim and SOXS to construct the synthetic spectra from the simulation data, and compare with the current low resolution observations from Chandra. Furthermore, we make mock spectra for the future mission ATHENA. With its unprecedented spectral resolution, emission line studies can be conducted for Milky Way-size galaxies for the first time. We will discuss how this will constrain the temperature, composition and velocity of galaxy coronae, which provide critical diagnostics for the feedback physics.
jeudi 20 juin 2019 - 11:30
Salle 281, Institut d'Astrophysique
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