Possible explanations for the formation of ear-like structures in young Type Ia supernova remnants

doi:10.1051/0004-6361/202449381

YNAO OpenIR > 星系类星体研究组

	Possible explanations for the formation of ear-like structures in young Type Ia supernova remnants
	Bao, Biwen 1,2; Wang, Yueyang 3; Yang CY(杨初源)4 ; Zhang, Li 1
发表期刊	Astronomy and Astrophysics
	2025-02-01
卷号	694
DOI	10.1051/0004-6361/202449381
产权排序	第4完成单位
收录类别	SCI ; EI
关键词	shock waves methods: numerical ISM: supernova remnants
摘要	Several young type Ia supernova remnants (SNRs) exhibit apparent axisymmetrical deviations from spherical symmetry, manifested as two opposite ear-like protrusions in their projected morphologies. The origin of this specific feature remains debated, with several physical mechanisms proposed as possible explanations. In this work, we propose two scenarios to explain the formation of ear-like structures: (i) the feedback of cosmic-ray (CR) acceleration via an effective adiabatic index, γeff, with spatial variations, and (ii) the large-scale pre-existing density gradient in the local interstellar medium (ISM). Our cylindrical hydrodynamic simulation results reveal that both scenarios can produce prominent protrusions well beyond the main shell, resembling the peculiar features observed in several young type Ia SNRs. Additionally, based on the detailed analysis of the simulation data, we attempt to elucidate the ear-formation process and suggest that the relative positions of contact discontinuity can serve as an observational diagnosis in pursuing the origin of ear-like structures. We also discuss the following points: (i) the theoretical prediction of type Ia SNRs with "ears" and the visibility of an ear-like structure in observations; (ii) the simulation-based inference concerning the emission properties of the ear-like regions and the implications of a qualitative comparison of our results with X-ray observations; and (iii) the potential combination of different scenarios. Despite various existing models, we tend to regard our proposed scenarios as potential alternatives, whereby the ear-like structures originate in pure ejecta-ISM interaction, distinct from the ejecta-circumstellar medium (CSM) or jet-CSM models.
资助项目	National Natural Science Foundation of China[12203042];National Natural Science Foundation of China[12233006];National Natural Science Foundation of China[202001AU070100];National Natural Science Foundation of China[202301AU070009]
项目资助者	National Natural Science Foundation of China[12203042, 12233006, 202001AU070100, 202301AU070009]
语种	英语
学科领域	天文学 ; 恒星与银河系
文章类型	Journal article (JA)
ISSN	0004-6361
URL	查看原文
EI入藏号	20250817916421
EI主题词	Supernovae
EI分类号	1302 Astronomy - 1302.1 Space Physics - 1302.1.2 Extraterrestrial Physics and Stellar Phenomena - 1303.1 Cosmology - 301.1.3 Aerodynamics (fluid flow) - 651 Aerodynamics - 941.9 Radiation Measurements
引用统计
文献类型	期刊论文
条目标识符	http://ir.ynao.ac.cn/handle/114a53/28176
专题	星系类星体研究组
作者单位	1.Department of Astronomy, Key Laboratory of Astroparticle Physics of Yunnan Province, Yunnan University, Kunming, 650091, China; 2.Key Laboratory of Statistical Modeling and Data Analysis of Yunnan Province, Yunnan University, Kunming, 650091, China; 3.Yunnan University of Chinese Medicine, Kunming, 650091, China; 4.Yunnan Observatories, Chinese Academy of Sciences, Kunming, 650011, China
推荐引用方式 GB/T 7714	Bao, Biwen,Wang, Yueyang,Yang CY,et al. Possible explanations for the formation of ear-like structures in young Type Ia supernova remnants[J]. Astronomy and Astrophysics,2025,694.
APA	Bao, Biwen,Wang, Yueyang,杨初源,&Zhang, Li.(2025).Possible explanations for the formation of ear-like structures in young Type Ia supernova remnants.Astronomy and Astrophysics,694.
MLA	Bao, Biwen,et al."Possible explanations for the formation of ear-like structures in young Type Ia supernova remnants".Astronomy and Astrophysics 694(2025).

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