On the emergence of a new instability during core-collapse of very massive stars. (arXiv:2112.00675v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Kalashnikov_I/0/1/0/all/0/1">I. Kalashnikov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Baranov_A/0/1/0/all/0/1">A. Baranov</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chardonnet_P/0/1/0/all/0/1">P. Chardonnet</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chechetkin_V/0/1/0/all/0/1">V. Chechetkin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Filina_A/0/1/0/all/0/1">A. Filina</a>
The process of uniform supernovae explosions (SNe) is well investigated for
all their types. However, observational data suggests that the SNe could be not
spherically-symmetric. Modern multi-dimensional simulations of SNe demonstrate
development of hydrodynamical instabilities during the explosion phase. But the
configuration of a star and inhomogeneities prior to explosion could strongly
affect how the SNe develops. In a number of papers on numerical modeling of
pair-instability supernovae explosion (PISNe) considered the case when
thermonuclear energy in the central region of a massive star is introduced by
the series of several hot spots. It leads to the appearance of many fragments
of hot matter behind the divergence shock wave. An observable manifestation of
this may be the presence of peaks on light curves of gamma-ray burst associated
with explosions of massive stars.
The physical nature of such inhomogeneities is not evident and the number and
size of spots is a conjecture. In this work, we study the possibility of
formation of these inhomogeneities at the stage of the core-collapse (CC) in a
massive star. To check this assumption, we chose analytic self-similar model of
CC and investigated stability of solutions obtained from it with respect to
small multidimensional perturbations. It shows there are no conditions where
the collapse of a very massive star may remain stable, although, for a less
massive star, it is possible. Using obtained relations, we found characteristic
features of developing instability, thereby making it possible to estimate the
amount and characteristic size of the inhomogeneities.
The process of uniform supernovae explosions (SNe) is well investigated for
all their types. However, observational data suggests that the SNe could be not
spherically-symmetric. Modern multi-dimensional simulations of SNe demonstrate
development of hydrodynamical instabilities during the explosion phase. But the
configuration of a star and inhomogeneities prior to explosion could strongly
affect how the SNe develops. In a number of papers on numerical modeling of
pair-instability supernovae explosion (PISNe) considered the case when
thermonuclear energy in the central region of a massive star is introduced by
the series of several hot spots. It leads to the appearance of many fragments
of hot matter behind the divergence shock wave. An observable manifestation of
this may be the presence of peaks on light curves of gamma-ray burst associated
with explosions of massive stars.
The physical nature of such inhomogeneities is not evident and the number and
size of spots is a conjecture. In this work, we study the possibility of
formation of these inhomogeneities at the stage of the core-collapse (CC) in a
massive star. To check this assumption, we chose analytic self-similar model of
CC and investigated stability of solutions obtained from it with respect to
small multidimensional perturbations. It shows there are no conditions where
the collapse of a very massive star may remain stable, although, for a less
massive star, it is possible. Using obtained relations, we found characteristic
features of developing instability, thereby making it possible to estimate the
amount and characteristic size of the inhomogeneities.
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