MHD Simulation of The Inner Galaxy with Radiative Cooling and Heating
Speaker: Kensuke Kakiuchi
Abstract:
Magnetic field is supposed to play a key role in the interstellar gas of the Galactic Center region (inner Galactic Bulge region). Observations show that the strength of the magnetic field within the central few hundred parsecs of the Galaxy is stronger than in the Galactic disk region, and its magnetic energy is comparable poor even surpasses the thermal and kinetic energy of the interstellar gas. Therefore, it is essential to study the role of the magnetic field to understand the behavior of the interstellar gas in the Galactic center region.
In this talk, we will present the results of 3D global magnetohydrodynamical simulations in the Galactic center region. A notable distinction from previous simulations is the inclusion of radiative cooling and heating effects. We found the formation of a mid-latitude low-plasma beta zone (dominated by magnetic field pressure), which would not have appeared in the model without radiative heating and cooling. While the thermal energy of the interstellar gas is lost because of radiative heating and cooling effects, the magnetic energy is independent of this direct effect and can contribute to the thickness that supports the interstellar gas clouds above the Galactic plane.In fact, it is difficult to explain the thickness of gas clouds in the Galactic center using only gas pressure scale heights, suggesting that the contribution of the magnetic field is important as an interpretation of this thickness.