Linear analysis on the growth of non-spherical perturbations in supersonic accretion flows

Kazuya Takahashi*, Shoichi Yamada

*この研究の対応する著者

研究成果: Article査読

17 被引用数 (Scopus)

抄録

We analyzed the growth of non-spherical perturbations in supersonic accretion flows. We have in mind an application to the post-bounce phase of core-collapse supernovae (CCSNe). Such non-spherical perturbations have been suggested by a series of papers by Arnett, who has numerically investigated violent convections in the outer layers of pre-collapse stars. Moreover, Couch & Ott demonstrated in their numerical simulations that such perturbations may lead to a successful supernova even for a progenitor that fails to explode without fluctuations. This study investigated the linear growth of perturbations during the infall onto a stalled shock wave. The linearized equations are solved as an initial and boundary value problem with the use of a Laplace transform. The background is a Bondi accretion flow whose parameters are chosen to mimic the 15 M progenitor model by Woosley & Heger, which is supposed to be a typical progenitor of CCSNe. We found that the perturbations that are given at a large radius grow as they flow down to the shock radius; the density perturbations can be amplified by a factor of 30, for example. We analytically show that the growth rate is proportional to l, the index of the spherical harmonics. We also found that the perturbations oscillate in time with frequencies that are similar to those of the standing accretion shock instability. This may have an implication for shock revival in CCSNe, which will be investigated in our forthcoming paper in more detail.

本文言語English
論文番号162
ジャーナルAstrophysical Journal
794
2
DOI
出版ステータスPublished - 2014 10月 20

ASJC Scopus subject areas

  • 天文学と天体物理学
  • 宇宙惑星科学

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