THE SILICON AND CALCIUM HIGH-VELOCITY FEATURES IN TYPE Ia SUPERNOVAE FROM EARLY TO MAXIMUM PHASES

	THE SILICON AND CALCIUM HIGH-VELOCITY FEATURES IN TYPE Ia SUPERNOVAE FROM EARLY TO MAXIMUM PHASES
	Zhao, Xulin 1,2; Wang, Xiaofeng 1; Maeda, Keiichi 2,3; Sai, Hanna 1; Zhang, Tianmeng4 ; Zhang, Jujia 5,6; Huang, Fang 1,7; Rui, Liming 1; Zhou, Qi 1; Mo, Jun 1
刊名	ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
	2015-09-01
卷号	220 期号:1
关键词	methods: data analysis supernovae: general techniques: spectroscopic
英文摘要	The high-velocity features (HVFs) in optical spectra of type Ia supernovae (SNe Ia) are examined with a large sample including very early-time spectra (e.g., t < -7 days). Multiple Gaussian fits are applied to examine the HVFs and their evolutions, using constraints on expansion velocities for the same species (i.e., Si II 5972 and Si II 6355). We find that strong HVFs tend to appear in SNe Ia with smaller decline rates (e.g., Delta m(15)(B) less than or similar to 1.4 mag), clarifying that the finding by Childress et al. for the Ca-HVFs in near-maximum-light spectra applies both to the SiHVFs and Ca-HVFs in the earlier phase. The Si-HVFs seem to be more common in rapidly expanding SNe Ia, which is different from the earlier result that Ca-HVFs are associated with SNe Ia that have slower Si II 6355 velocities at maximum light (i.e., V-max(Si)). Moreover, SNe Ia with both stronger HVFs at early phases and larger V-max(Si) are found to have noticeably redder B - V colors and to occur preferentially in the inner regions of their host galaxies, while those with stronger HVFs but smaller V-max(Si) show opposite tendencies, suggesting that these two subclasses have different explosion environments and their HVFs may have different origins. We further examine the relationships between the absorption features of Si II 6355 and Ca II IR lines, and find that their photospheric components are well correlated in velocity and strength but that the corresponding HVFs show larger scatter. These results cannot be explained with ionization and/or thermal processes alone, and different mechanisms are required for the creation of HVF-forming regions in SNe Ia.
收录类别	SCI
语种	英语
WOS记录号	WOS:000364049900020
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/5540]
专题	国家天文台_光学天文研究部
作者单位	1.Tsinghua Univ, Dept Phys, Ctr Astrophys, Beijing 100084, Peoples R China 2.Kyoto Univ, Dept Astron, Kyoto 6068502, Japan 3.Univ Tokyo, Kavli Inst Phys & Math Universe WPI, Kashiwa, Chiba 2778583, Japan 4.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China 5.Chinese Acad Sci, Yunnan Observ, Kunming 650216, Peoples R China 6.Chinese Acad Sci, Key Lab Struct & Evolut Celestial Objects, Kunming 650216, Peoples R China 7.Beijing Normal Univ, Dept Astron, Beijing 100875, Peoples R China
推荐引用方式 GB/T 7714	Zhao, Xulin,Wang, Xiaofeng,Maeda, Keiichi,et al. THE SILICON AND CALCIUM HIGH-VELOCITY FEATURES IN TYPE Ia SUPERNOVAE FROM EARLY TO MAXIMUM PHASES[J]. ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES,2015,220(1).
APA	Zhao, Xulin.,Wang, Xiaofeng.,Maeda, Keiichi.,Sai, Hanna.,Zhang, Tianmeng.,...&Mo, Jun.(2015).THE SILICON AND CALCIUM HIGH-VELOCITY FEATURES IN TYPE Ia SUPERNOVAE FROM EARLY TO MAXIMUM PHASES.ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES,220(1).
MLA	Zhao, Xulin,et al."THE SILICON AND CALCIUM HIGH-VELOCITY FEATURES IN TYPE Ia SUPERNOVAE FROM EARLY TO MAXIMUM PHASES".ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES 220.1(2015).