Title: A New Model for Electron-capture Supernovae in Galactic Chemical Evolution

Abstract

We examine the contribution of electron-capture supernovae (ECSNe), low-mass SNe from collapsing Fe cores (FeCCSNe), and rotating massive stars to the chemical composition of the Galaxy. Our model includes contributions to chemical evolution from both thermonuclear ECSNe (tECSNe) and gravitational collapse ECSNe (cECSNe). We show that if ECSNe are predominantly gravitational collapse SNe but about 15% are partial thermonuclear explosions, the model is able to reproduce the solar abundances of several important and problematic isotopes including $${}^{48}\mathrm{Ca}$$, $${}^{50}\mathrm{Ti}$$, and ⁵⁴Cr together with ⁵⁸Fe, ⁶⁴Ni, ⁸²Se, and ⁸⁶Kr and several of the Zn–Zr isotopes. A model in which no cECSNe occur, only tECSNe with low-mass FeCCSNe or rotating massive stars, proves also very successful at reproducing the solar abundances for these isotopes. Despite the small mass range for the progenitors of ECSNe and low-mass FeCCSNe, the large production factors suffice for the solar inventory of the above isotopes. Our model is compelling because it introduces no new tensions with the solar abundance distribution for a Milky Way model—only tending to improve the model predictions for several isotopes. Here, the proposed astrophysical production model thus provides a natural and elegant way to explain one of the last uncharted territories on the periodic table of astrophysical element production.

Authors:

Jones, Samuel  ^[1];

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Côté, Benoit  ^[2];

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Röpke, Friedrich K. ^[3]; Wanajo, Shinya ^[4]

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+ Show Author Affiliations

1. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2. Hungarian Academy of Sciences, Budapest (Hungary); Michigan State Univ., East Lansing, MI (United States); Joint Institute for Nuclear Astrophysics—Center for the Evolution of the Elements, East Lansing, MI (United States)
3. Zentrum für Astronomie der Univ. Heidelberg, Heidelberg (Germany); Heidelberg Inst. for Theoretical Studies, Heidelberg (Germany)
4. Max Planck Inst. for Gravitational Physics (Albert Einstein Institute), Potsdam-Golm (Germany); Sophia Univ., Tokyo (Japan); RIKEN, Saitama (Japan)

Publication Date:

2019-09-10

Research Org.:

Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

Sponsoring Org.:

USDOE Laboratory Directed Research and Development (LDRD) Program

OSTI Identifier:

1570629

Report Number(s):

LA-UR-19-25987
Journal ID: ISSN 1538-4357; TRN: US2100327

Grant/Contract Number:  

89233218CNA000001

Resource Type:

Accepted Manuscript

Journal Name:

The Astrophysical Journal (Online)

Additional Journal Information:

Journal Name: The Astrophysical Journal (Online); Journal Volume: 882; Journal Issue: 2; Journal ID: ISSN 1538-4357

Publisher:

Institute of Physics (IOP)

Country of Publication:

United States

Language:

English

Subject:

79 ASTRONOMY AND ASTROPHYSICS; nuclear reactions; nucleosynthesis; abundances; Sun: abundances; stars: evolution; supernovae: general; Galaxy: abundances