2017ApJ...836L..21N -
Astrophys. J., 836, L21-L21 (2017/February-3)
The intermediate r-process in core-collapse supernovae driven by the magneto-rotational instability.
NISHIMURA N., SAWAI H., TAKIWAKI T., YAMADA S. and THIELEMANN F.-K.
Abstract (from CDS):
We investigated r-process nucleosynthesis in magneto-rotational supernovae, based on a new explosion mechanism induced by the magneto-rotational instability (MRI). A series of axisymmetric magneto-hydrodynamical simulations with detailed microphysics including neutrino heating is performed, numerically resolving the MRI. Neutrino-heating dominated explosions, enhanced by magnetic fields, showed mildly neutron-rich ejecta producing nuclei up to A∼130 (i.e., the weak r-process), while explosion models with stronger magnetic fields reproduce a solar-like r-process pattern. More commonly seen abundance patterns in our models are in between the weak and regular r-process, producing lighter and intermediate-mass nuclei. These intermediate r-processes exhibit a variety of abundance distributions, compatible with several abundance patterns in r-process-enhanced metal-poor stars. The amount of Eu ejecta ∼10–5 M☉ in magnetically driven jets agrees with predicted values in the chemical evolution of early galaxies. In contrast, neutrino-heating dominated explosions have a significant amount of Fe (56Ni) and Zn, comparable to regular supernovae and hypernovae, respectively. These results indicate magneto-rotational supernovae can produce a wide range of heavy nuclei from iron-group to r-process elements, depending on the explosion dynamics.
Abstract Copyright:
© 2017. The American Astronomical Society. All rights reserved.
Journal keyword(s):
gamma-ray burst: general - magnetohydrodynamics MHD - neutrinos - nuclear reactions, nucleosynthesis, abundances - stars: neutron - supernovae: general - supernovae: general
Simbad objects:
3
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