Poster abstract
The fragmentation of expanding shells
Abstract
We investigate the gravitational fragmentation of expanding shells by using the three-dimensional Godunov smoothed particle hydrodynamics.
We calculate the evolution of shells which expand into the uniform cold gas with a steady energy input from the center. In order to save the number of SPH particles and to resolve the thickness of the shell, we consider not the whole but a part of the shell by imposing on the rotational periodic boundary condition. We find that the gravitational instability in the expanding shells grows with a larger growth rate and a shorter wavelength than the prediction of the linear analysis under
the thin-shell approximation by Elmegreen (1994). This large growth rate is attributed to the thermal pressure of the hot bubble which pushes the shells outward. In our poster, we will present the detailed mechanism of the gravitational fragmentation of expanding shells.
We calculate the evolution of shells which expand into the uniform cold gas with a steady energy input from the center. In order to save the number of SPH particles and to resolve the thickness of the shell, we consider not the whole but a part of the shell by imposing on the rotational periodic boundary condition. We find that the gravitational instability in the expanding shells grows with a larger growth rate and a shorter wavelength than the prediction of the linear analysis under
the thin-shell approximation by Elmegreen (1994). This large growth rate is attributed to the thermal pressure of the hot bubble which pushes the shells outward. In our poster, we will present the detailed mechanism of the gravitational fragmentation of expanding shells.