Silicon carbide grains of type C provide evidence for the production of the unstable isotope 32Si in supernovae

M. Pignatari, E. Zinner, M. G. Bertolli, R. Trappitsch, P. Hoppe, T. Rauscher, C. Fryer, F. Herwig, R. Hirschi, Francis Timmes, F. K. Thielemann

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Carbon-rich grains are observed to condense in the ejecta of recent core-collapse supernovae (SNe) within a year after the explosion. Silicon carbide grains of type X are C-rich grains with isotopic signatures of explosive SN nucleosynthesis have been found in primitive meteorites. Much rarer silicon carbide grains of type C are a special sub-group of SiC grains from SNe. They show peculiar abundance signatures for Si and S, isotopically heavy Si, and isotopically light S, which appear to be in disagreement with model predictions. We propose that C grains are formed mostly from C-rich stellar material exposed to lower SN shock temperatures than the more common type X grains. In this scenario, extreme 32S enrichments observed in C grains may be explained by the presence of short-lived 32Si (τ1/2 = 153 yr) in the ejecta, produced by neutron capture processes starting from the stable Si isotopes. No mixing from deeper Si-rich material and/or fractionation of Si from S due to molecular chemistry is needed to explain the 32S enrichments. The abundance of 32Si in the grains can provide constraints on the neutron density reached during the SN explosion in the C-rich He shell material. The impact of the large uncertainty of the neutron capture cross sections in the 32Si region is discussed.

Original languageEnglish (US)
Article numberL7
JournalAstrophysical Journal Letters
Volume771
Issue number1
DOIs
StatePublished - Jul 1 2013

Fingerprint

silicon carbides
silicon
supernovae
isotopes
isotope
ejecta
explosion
meteorite
explosive
stable isotope
fractionation
cross section
shell
neutrons
explosions
carbon
prediction
signatures
material
temperature

Keywords

  • stars: abundances
  • stars: evolution
  • stars: interiors
  • stars: massive

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Pignatari, M., Zinner, E., Bertolli, M. G., Trappitsch, R., Hoppe, P., Rauscher, T., ... Thielemann, F. K. (2013). Silicon carbide grains of type C provide evidence for the production of the unstable isotope 32Si in supernovae. Astrophysical Journal Letters, 771(1), [L7]. https://doi.org/10.1088/2041-8205/771/1/L7

Silicon carbide grains of type C provide evidence for the production of the unstable isotope 32Si in supernovae. / Pignatari, M.; Zinner, E.; Bertolli, M. G.; Trappitsch, R.; Hoppe, P.; Rauscher, T.; Fryer, C.; Herwig, F.; Hirschi, R.; Timmes, Francis; Thielemann, F. K.

In: Astrophysical Journal Letters, Vol. 771, No. 1, L7, 01.07.2013.

Research output: Contribution to journalArticle

Pignatari, M, Zinner, E, Bertolli, MG, Trappitsch, R, Hoppe, P, Rauscher, T, Fryer, C, Herwig, F, Hirschi, R, Timmes, F & Thielemann, FK 2013, 'Silicon carbide grains of type C provide evidence for the production of the unstable isotope 32Si in supernovae', Astrophysical Journal Letters, vol. 771, no. 1, L7. https://doi.org/10.1088/2041-8205/771/1/L7
Pignatari, M. ; Zinner, E. ; Bertolli, M. G. ; Trappitsch, R. ; Hoppe, P. ; Rauscher, T. ; Fryer, C. ; Herwig, F. ; Hirschi, R. ; Timmes, Francis ; Thielemann, F. K. / Silicon carbide grains of type C provide evidence for the production of the unstable isotope 32Si in supernovae. In: Astrophysical Journal Letters. 2013 ; Vol. 771, No. 1.
@article{c4400ec628184f9c9f58e2ba945c53da,
title = "Silicon carbide grains of type C provide evidence for the production of the unstable isotope 32Si in supernovae",
abstract = "Carbon-rich grains are observed to condense in the ejecta of recent core-collapse supernovae (SNe) within a year after the explosion. Silicon carbide grains of type X are C-rich grains with isotopic signatures of explosive SN nucleosynthesis have been found in primitive meteorites. Much rarer silicon carbide grains of type C are a special sub-group of SiC grains from SNe. They show peculiar abundance signatures for Si and S, isotopically heavy Si, and isotopically light S, which appear to be in disagreement with model predictions. We propose that C grains are formed mostly from C-rich stellar material exposed to lower SN shock temperatures than the more common type X grains. In this scenario, extreme 32S enrichments observed in C grains may be explained by the presence of short-lived 32Si (τ1/2 = 153 yr) in the ejecta, produced by neutron capture processes starting from the stable Si isotopes. No mixing from deeper Si-rich material and/or fractionation of Si from S due to molecular chemistry is needed to explain the 32S enrichments. The abundance of 32Si in the grains can provide constraints on the neutron density reached during the SN explosion in the C-rich He shell material. The impact of the large uncertainty of the neutron capture cross sections in the 32Si region is discussed.",
keywords = "stars: abundances, stars: evolution, stars: interiors, stars: massive",
author = "M. Pignatari and E. Zinner and Bertolli, {M. G.} and R. Trappitsch and P. Hoppe and T. Rauscher and C. Fryer and F. Herwig and R. Hirschi and Francis Timmes and Thielemann, {F. K.}",
year = "2013",
month = "7",
day = "1",
doi = "10.1088/2041-8205/771/1/L7",
language = "English (US)",
volume = "771",
journal = "Astrophysical Journal Letters",
issn = "2041-8205",
publisher = "IOP Publishing Ltd.",
number = "1",

}

TY - JOUR

T1 - Silicon carbide grains of type C provide evidence for the production of the unstable isotope 32Si in supernovae

AU - Pignatari, M.

AU - Zinner, E.

AU - Bertolli, M. G.

AU - Trappitsch, R.

AU - Hoppe, P.

AU - Rauscher, T.

AU - Fryer, C.

AU - Herwig, F.

AU - Hirschi, R.

AU - Timmes, Francis

AU - Thielemann, F. K.

PY - 2013/7/1

Y1 - 2013/7/1

N2 - Carbon-rich grains are observed to condense in the ejecta of recent core-collapse supernovae (SNe) within a year after the explosion. Silicon carbide grains of type X are C-rich grains with isotopic signatures of explosive SN nucleosynthesis have been found in primitive meteorites. Much rarer silicon carbide grains of type C are a special sub-group of SiC grains from SNe. They show peculiar abundance signatures for Si and S, isotopically heavy Si, and isotopically light S, which appear to be in disagreement with model predictions. We propose that C grains are formed mostly from C-rich stellar material exposed to lower SN shock temperatures than the more common type X grains. In this scenario, extreme 32S enrichments observed in C grains may be explained by the presence of short-lived 32Si (τ1/2 = 153 yr) in the ejecta, produced by neutron capture processes starting from the stable Si isotopes. No mixing from deeper Si-rich material and/or fractionation of Si from S due to molecular chemistry is needed to explain the 32S enrichments. The abundance of 32Si in the grains can provide constraints on the neutron density reached during the SN explosion in the C-rich He shell material. The impact of the large uncertainty of the neutron capture cross sections in the 32Si region is discussed.

AB - Carbon-rich grains are observed to condense in the ejecta of recent core-collapse supernovae (SNe) within a year after the explosion. Silicon carbide grains of type X are C-rich grains with isotopic signatures of explosive SN nucleosynthesis have been found in primitive meteorites. Much rarer silicon carbide grains of type C are a special sub-group of SiC grains from SNe. They show peculiar abundance signatures for Si and S, isotopically heavy Si, and isotopically light S, which appear to be in disagreement with model predictions. We propose that C grains are formed mostly from C-rich stellar material exposed to lower SN shock temperatures than the more common type X grains. In this scenario, extreme 32S enrichments observed in C grains may be explained by the presence of short-lived 32Si (τ1/2 = 153 yr) in the ejecta, produced by neutron capture processes starting from the stable Si isotopes. No mixing from deeper Si-rich material and/or fractionation of Si from S due to molecular chemistry is needed to explain the 32S enrichments. The abundance of 32Si in the grains can provide constraints on the neutron density reached during the SN explosion in the C-rich He shell material. The impact of the large uncertainty of the neutron capture cross sections in the 32Si region is discussed.

KW - stars: abundances

KW - stars: evolution

KW - stars: interiors

KW - stars: massive

UR - http://www.scopus.com/inward/record.url?scp=84879953920&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84879953920&partnerID=8YFLogxK

U2 - 10.1088/2041-8205/771/1/L7

DO - 10.1088/2041-8205/771/1/L7

M3 - Article

AN - SCOPUS:84879953920

VL - 771

JO - Astrophysical Journal Letters

JF - Astrophysical Journal Letters

SN - 2041-8205

IS - 1

M1 - L7

ER -