NUCLEOSYNTHESIS IN ELECTRON CAPTURE SUPERNOVAE OF ASYMPTOTIC GIANT BRANCH STARS

Journal Article · Fri Apr 10 04:00:00 EDT 2009 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/695/1/208; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21296264

Wanajo, S; Nomoto, K ^[1]; Janka, H -T; Kitaura, F S

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1. Institute for the Physics and Mathematics of the Universe, University of Tokyo, Kashiwa, Chiba 277-8582 (Japan)

We examine nucleosynthesis in the electron capture supernovae of progenitor asymptotic giant branch stars with an O-Ne-Mg core (with the initial stellar mass of 8.8 M {sub sun}). Thermodynamic trajectories for the first 810 ms after core bounce are taken from a recent state-of-the-art hydrodynamic simulation. The presented nucleosynthesis results are characterized by a number of distinct features that are not shared with those of other supernovae from the collapse of stars with iron core (with initial stellar masses of more than 10 M {sub sun}). First is the small amount of {sup 56}Ni (0.002-0.004 M {sub sun}) in the ejecta, which can be an explanation for the observed properties of faint supernovae such as SNe 2008S and 1997D. In addition, the large Ni/Fe ratio is in reasonable agreement with the spectroscopic result of the Crab nebula (the relic of SN 1054). Second is the large production of {sup 64}Zn, {sup 70}Ge, light p-nuclei ({sup 74}Se, {sup 78}Kr, {sup 84}Sr, and {sup 92}Mo), and in particular, {sup 90}Zr, which originates from the low Y{sub e} (0.46-0.49, the number of electrons per nucleon) ejecta. We find, however, that only a 1%-2% increase of the minimum Y{sub e} moderates the overproduction of {sup 90}Zr. In contrast, the production of {sup 64}Zn is fairly robust against a small variation of Y{sub e} . This provides the upper limit of the occurrence of this type of events to be about 30% of all core-collapse supernovae.

• OSTI ID: 21296264
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 1 Vol. 695; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS
ABUNDANCE
ASYMPTOTIC SOLUTIONS
CRAB NEBULA
ELECTRON CAPTURE
GERMANIUM 70
KRYPTON 78
MOLYBDENUM 92
NICKEL 56
NUCLEAR REACTIONS
NUCLEOSYNTHESIS
SELENIUM 74
STRONTIUM 84
SUPERNOVAE
ZINC 64
ZIRCONIUM 90