Polarimetry of the Type Ia supernova SN 1996X

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	Polarimetry of the Type Ia supernova SN 1996X
	Wang, LF ; Wheeler, JC ; Hoflich, P
刊名	ASTROPHYSICAL JOURNAL
	1997-02-10
卷号	476 期号:1 页码:L27-L30
关键词	supernovae, individual (SN 1996X) polarization radiative transfer
ISSN号	0004-637X
英文摘要	We present broadband and spectropolarimetry of the Type Ia SN 1996X obtained on 1996 April 14 (UT), and broadband polarimetry of SN 1996X on 1996 May 22 (UT), i.e., about 1 week before and 4 weeks after optical maximum, respectively. The Stokes parameters derived from the broadband polarimetry are consistent with zero polarization. The spectropolarimetry, however, shows broad spectral features that are due intrinsically to an asymmetric supernova atmosphere. The degree of this intrinsic component is low (similar to 0.3%). Unlike polarization in Type II SN, the features of SN 1996X are much more richly structured and show no strong correlation with the features in the flux. Model calculations show that the polarization is produced by Thomson scattering but the spectral features are governed by line blending. Consequently, for similar geometrical distortions, the residual polarization is smaller by about a factor of 2-3 compared to the less blended Type II atmosphere, making it intrinsically harder to detect asphericities in Type Ia. The model features are in general agreement with the observations. Taken literally, this implies an asphericity of approximate to 11% in the chemical distribution in the region of partial burning. This may not imperil the use of Type Ia supernovae as standard candles for distance determination, but nonetheless poses a source of uncertainty. SN 1996X is the first Type Ia supernova for which spectropolarimetry revealed a polarized component intrinsic to the supernova and the first Type Ia supernova with spectropolarimetry well prior to optical maximum.
WOS关键词	INTERSTELLAR POLARIZATION ; SN-1987A POLARIMETRY ; SPECTROPOLARIMETRY ; SN-1993J
WOS研究方向	Astronomy & Astrophysics
语种	英语
出版者	UNIV CHICAGO PRESS
WOS记录号	WOS:A1997WG53500007
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/37427]
专题	中国科学院国家天文台
通讯作者	Wang, LF
作者单位	1.CHINESE ACAD SCI,BEIJING ASTRON OBSERV,BEIJING 100080,PEOPLES R CHINA 2.UNIV BASEL,INST THEORET PHYS,CH-4056 BASEL,SWITZERLAND 3.HARVARD SMITHSONIAN CTR ASTROPHYS,CAMBRIDGE,MA 02138 4.UNIV TEXAS,MCDONALD OBSERV,AUSTIN,TX 78712
推荐引用方式 GB/T 7714	Wang, LF,Wheeler, JC,Hoflich, P. Polarimetry of the Type Ia supernova SN 1996X[J]. ASTROPHYSICAL JOURNAL,1997,476(1):L27-L30.
APA	Wang, LF,Wheeler, JC,&Hoflich, P.(1997).Polarimetry of the Type Ia supernova SN 1996X.ASTROPHYSICAL JOURNAL,476(1),L27-L30.
MLA	Wang, LF,et al."Polarimetry of the Type Ia supernova SN 1996X".ASTROPHYSICAL JOURNAL 476.1(1997):L27-L30.