The effects of a hot gaseous halo in galaxy major mergers

Understand

Cosmological hydrodynamical simulations as well as observations indicate that spiral galaxies are comprised of five different components: dark matter halo, stellar disc, stellar bulge, gaseous disc and gaseous halo.

• While the first four components have been extensively considered in numerical simulations of binary galaxy mergers, the effect of a hot gaseous halo has usually been neglected even though it can contain up to 80% of the total gas within the galaxy virial radius.
• We present a series of hydrodynamic simulations of major mergers of disc galaxies, that for the first time include a diffuse, rotating, hot gaseous halo.
• Through cooling and accretion, the hot halo can dissipate and refuel the cold gas disc before and after a merger.