Astronomy and Astrophysics – Astrophysics – Galaxy Astrophysics
Scientific paper
2011-03-15
Astronomy and Astrophysics
Astrophysics
Galaxy Astrophysics
13 pages, 13 figures, to be published in the Astrophysical Journal
Scientific paper
We perform a linear perturbation analysis of expanding shells driven by expansions of HII regions. The ambient gas is assumed to be uniform. As an unperturbed state, we develop a semi-analytic method for deriving the time evolution of the density profile across the thickness. It is found that the time evolution of the density profile can be divided into three evolutionary phases, deceleration-dominated, intermediate, and self-gravity-dominated phases. The density peak moves relatively from the shock front to the contact discontinuity as the shell expands. We perform a linear analysis taking into account the asymmetric density profile obtained by the semi-analytic method, and imposing the boundary conditions for the shock front and the contact discontinuity while the evolutionary effect of the shell is neglected. It is found that the growth rate is enhanced compared with the previous studies based on the thin-shell approximation. This is due to the boundary effect of the contact discontinuity and asymmetric density profile that were not taken into account in previous works.
Inutsuka Shu-ichiro
Iwasaki Kazunari
Tsuribe Toru
No associations
LandOfFree
Gravitational Fragmentation of Expanding Shells. I. Linear Analysis does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Gravitational Fragmentation of Expanding Shells. I. Linear Analysis, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gravitational Fragmentation of Expanding Shells. I. Linear Analysis will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-138979