95 research outputs found
Pulsational Pair-instability Supernovae. I. Pre-collapse Evolution and Pulsational Mass Ejection
We calculate the evolution of massive stars, which undergo pulsational
pair-instability (PPI) when the O-rich core is formed. The evolution from the
main-sequence through the onset of PPI is calculated for stars with the initial
masses of and metallicities of
. Because of mass loss, is necessary for stars
to form He cores massive enough (i.e., mass ) to undergo PPI. The
hydrodynamical phase of evolution from PPI through the beginning of Fe core
collapse is calculated for the He cores with masses of and
. During PPI, electron-positron pair production causes a rapid
contraction of the O-rich core which triggers explosive O-burning and a
pulsation of the core. We study the mass dependence of the pulsation dynamics,
thermodynamics, and nucleosynthesis. The pulsations are stronger for more
massive He cores and result in such a large amount of mass ejection such as for He cores. These He cores eventually
undergo Fe-core collapse. The He core undergoes complete
disruption and becomes a pair-instability supernova. The H-free circumstellar
matter ejected around these He cores is massive enough for to explain the
observed light curve of Type I (H-free) superluminous supernovae with
circumstellar interaction. We also note that the mass ejection sets the maximum
mass of black holes (BHs) to be , which is consistent with
the masses of BHs recently detected by VIRGO and aLIGO.Comment: 33 pages, 57 figures, submitted at 29 January 2019, revised at 16
October 2019, accepted at 20 October 2019; published 11 December 2019.
References and metadata update
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