TY - JOUR
T1 - A Nucleosynthetic Origin for the Southwestern Fe-rich Structure in Kepler's Supernova Remnant
AU - Sato, Toshiki
AU - Bravo, Eduardo
AU - Badenes, Carles
AU - Hughes, John J.
AU - Williams, Brian J.
AU - Yamaguchi, Hiroya
N1 - Funding Information:
2020-02-20 2020-02-18 15:14:13 cgi/release: Article released bin/incoming: New from .zip JSPS JP18H05865 JSPS JP19K14739 RIKEN Special Postdoctoral Researchers Program RIKEN FY 2019 Incentive Research Projects NASA NNX15AK71G yes
Publisher Copyright:
© 2020. The American Astronomical Society. All rights reserved.
PY - 2020/2/20
Y1 - 2020/2/20
N2 - Chandra X-ray observations of Kepler's supernova remnant indicate the existence of a high-speed Fe-rich ejecta structure in the southwestern region. We report strong K-shell emission from Fe-peak elements (Cr, Mn, Fe, Ni), as well as Ca, in this Fe-rich structure, implying that those elements could be produced in the inner area of the exploding white dwarf. We found Ca/Fe, Cr/Fe, Mn/Fe, and Ni/Fe mass ratios of 1.0%-4.1%, 1.0%-4.6%, 1%-11%, and 2%-30%, respectively. In order to constrain the burning regime that could produce this structure, we compared these observed mass ratios with those in 18 one-dimensional Type Ia nucleosynthesis models (including both near-M Ch and sub-M Ch explosion models). The observed mass ratios agree well with those around the middle layer of incomplete Si burning in Type Ia nucleosynthesis models with a peak temperature of ∼(5.0-5.3) × 109 K and a high metallicity, Z > 0.0225. Based on our results, we infer the necessity for some mechanism to produce protruding Fe-rich clumps dominated by incomplete Si-burning products during the explosion. We also discuss the future perspectives of X-ray observations of Fe-rich structures in other Type Ia supernova remnants.
AB - Chandra X-ray observations of Kepler's supernova remnant indicate the existence of a high-speed Fe-rich ejecta structure in the southwestern region. We report strong K-shell emission from Fe-peak elements (Cr, Mn, Fe, Ni), as well as Ca, in this Fe-rich structure, implying that those elements could be produced in the inner area of the exploding white dwarf. We found Ca/Fe, Cr/Fe, Mn/Fe, and Ni/Fe mass ratios of 1.0%-4.1%, 1.0%-4.6%, 1%-11%, and 2%-30%, respectively. In order to constrain the burning regime that could produce this structure, we compared these observed mass ratios with those in 18 one-dimensional Type Ia nucleosynthesis models (including both near-M Ch and sub-M Ch explosion models). The observed mass ratios agree well with those around the middle layer of incomplete Si burning in Type Ia nucleosynthesis models with a peak temperature of ∼(5.0-5.3) × 109 K and a high metallicity, Z > 0.0225. Based on our results, we infer the necessity for some mechanism to produce protruding Fe-rich clumps dominated by incomplete Si-burning products during the explosion. We also discuss the future perspectives of X-ray observations of Fe-rich structures in other Type Ia supernova remnants.
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U2 - 10.3847/1538-4357/ab6aa2
DO - 10.3847/1538-4357/ab6aa2
M3 - Article
AN - SCOPUS:85081560247
SN - 0004-637X
VL - 890
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 104
ER -