Discovery of a Highly Neutronized Ejecta Clump in the Type Ia Supernova Remnant 3C 397

Ohshiro, Yuken and Yamaguchi, Hiroya and Leung, Shing-Chi and Nomoto, Ken’ichi and Sato, Toshiki and Tanaka, Takaaki and Okon, Hiromichi and Fisher, Robert and Petre, Robert and Williams, Brian J. (2021) Discovery of a Highly Neutronized Ejecta Clump in the Type Ia Supernova Remnant 3C 397. The Astrophysical Journal Letters, 913 (2). L34. ISSN 2041-8205

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Abstract

The supernova remnant (SNR) 3C 397 is thought to originate from a Type Ia supernova (SN Ia) explosion of a near-Chandrasekhar-mass (MCh) progenitor, based on the enhanced abundances of Mn and Ni revealed by previous X-ray study with Suzaku. Here we report follow-up XMM-Newton observations of this SNR, conducted with the aim of investigating the detailed spatial distribution of the Fe-peak elements. We have discovered an ejecta clump with extremely high abundances of Ti and Cr, in addition to Mn, Fe, and Ni, in the southern part of the SNR. The Fe mass of this ejecta clump is estimated to be ∼0.06 M⊙, under the assumption of a typical Fe yield for SNe Ia (i.e., ∼0.8 M⊙). The observed mass ratios among the Fe-peak elements and Ti require substantial neutronization that is achieved only in the innermost regions of a near-MCh SN Ia with a central density of ρc ∼ 5 × 109 g cm−3, significantly higher than typically assumed for standard near-MCh SNe Ia (ρc ∼ 2 × 109 g cm−3). The overproduction of the neutron-rich isotopes (e.g., 50Ti and 54Cr) is significant in such high-ρc SNe Ia, with respect to the solar composition. Therefore, if 3C 397 is a typical high-ρc near-MCh SN Ia remnant, the solar abundances of these isotopes could be reproduced by the mixture of the high- and low-ρc near-MCh and sub-MCh Type Ia events, with ≲20% being high-ρc near-MCh.

Item Type: Article
Subjects: Middle East Library > Physics and Astronomy
Depositing User: Unnamed user with email support@middle-eastlibrary.com
Date Deposited: 10 May 2023 08:48
Last Modified: 19 Sep 2024 09:38
URI: http://editor.openaccessbook.com/id/eprint/771

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