Speaker
Description
We adopt a new kind of one-dimensional model instead of the isothermal sphere to describe the radial distribution of hot gas in the L-Galaxies semi-analytic model. The hot gas halo can be divided into two parts according to the ratio of the local thermal instability time-scale and the free-fall time-scale: a cool core with tTI/tff = 10 and a stable outer halo with tTI/tff > 10. We update the prescriptions of cooling, feedback, and stripping based on the new hot gas profiles, and then reproduce several X-ray observational results like the radial profiles of hot gas density, and the scaling relations of X-ray luminosity and temperature. We find: (1) Consistent with observations, flatter density profiles in halo centers produce lower X-ray emission than an isothermal sphere; (2) Cool core regions prone to precipitation have higher gas temperature than the virial temperature, and a larger TX/T200 ratio in smaller haloes leads to a steeper slope in the LX-TX relation; (3) The ionized gas in the unbounded reservoir and low-temperature intergalactic gas in low-mass haloes could be the main components of the halo 'missing baryons'.
Based on the model outputs of hot gas profiles. We make the mock observations for hot gas components, we generate the mock X-ray spectra with SOXS package and derive the mock images in soft X-ray band. We also make some predictions for the future survey of hot baryons by X-ray facilities (e.g.for HUBS), which should help the target selection for future observations.
