Velocity Dispersion of Ionized Gas and Multiple Supernova Explosions

[摘要] We use 3D numerical simulations to study the evolution of the H α intensity and velocity dispersion for single and multiple supernova (SN) explosions. We find that the I H α – σ diagram obtained for simulated gas flows is similar in shape to that observed in dwarf galaxies. We conclude that colliding SN shells with significant difference in age are responsible for high velocity dispersion that reaches up to ≳ 100 km s −1 . Such a high velocity dispersion could be hardly obtained for a single SN remnant. Peaks of velocity dispersion in the I H α – σ diagram may correspond to several isolated or merged SN remnants with moderately different ages. Degrading the spatial resolution in the H α intensity and velocity dispersion maps makes the simulated I H α – σ diagrams close to those observed in dwarf galaxies not only in shape, but also quantitatively.

[关键词] galaxies ISM;ISM bubbles;ISM supernova remnants;ISM kinematics and dynamics;shock waves;methods numerical