TY - JOUR
T1 - Pre-explosion dynamo in the cores of massive stars
AU - Soker, Noam
AU - Gilkis, Avishai
N1 - Publisher Copyright:
© 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2017/1/1
Y1 - 2017/1/1
N2 - We propose a speculative scenario where dynamo amplification of magnetic fields in the core convective shells of massive stars, tens of years to hours before they explode, leads to envelope expansion and enhanced mass-loss rate, resulting in pre-explosion outbursts (PEOs). The convective luminosity in the burning shells of carbon, neon, oxygen, and then silicon, are very high. Based on the behaviour of active main-sequence stars, we speculate that the convective shells can trigger magnetic activity with a power of about 0.001 times the convective luminosity. Magnetic flux tubes might buoy outward and deposit their energy in the outer parts of the envelope. This in turn might lead to the expansion of the envelope and to an enhanced mass-loss rate. If a close binary companion is present, mass transfer might take place and lead to an energetic outburst. The magnetic activity requires minimum core rotation and that the stochastic magnetic activity be on its high phase. Only in rare cases these conditions are met, accounting for that only the minority of core collapse supernovae experience PEO. Such a pre-explosion magnetic activity might have implications for the explosion mechanism itself.
AB - We propose a speculative scenario where dynamo amplification of magnetic fields in the core convective shells of massive stars, tens of years to hours before they explode, leads to envelope expansion and enhanced mass-loss rate, resulting in pre-explosion outbursts (PEOs). The convective luminosity in the burning shells of carbon, neon, oxygen, and then silicon, are very high. Based on the behaviour of active main-sequence stars, we speculate that the convective shells can trigger magnetic activity with a power of about 0.001 times the convective luminosity. Magnetic flux tubes might buoy outward and deposit their energy in the outer parts of the envelope. This in turn might lead to the expansion of the envelope and to an enhanced mass-loss rate. If a close binary companion is present, mass transfer might take place and lead to an energetic outburst. The magnetic activity requires minimum core rotation and that the stochastic magnetic activity be on its high phase. Only in rare cases these conditions are met, accounting for that only the minority of core collapse supernovae experience PEO. Such a pre-explosion magnetic activity might have implications for the explosion mechanism itself.
KW - Dynamo
KW - Magnetic fields
KW - Stars: massive
KW - Supernovae: general
UR - http://www.scopus.com/inward/record.url?scp=85023742289&partnerID=8YFLogxK
U2 - 10.1093/mnras/stw2546
DO - 10.1093/mnras/stw2546
M3 - 文章
AN - SCOPUS:85023742289
VL - 464
SP - 3249
EP - 3255
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
SN - 0035-8711
IS - 3
ER -