MAGNETAR GIANT FLARES IN MULTIPOLAR MAGNETIC FIELDS. II. FLUX ROPE ERUPTIONS WITH CURRENT SHEETS

	MAGNETAR GIANT FLARES IN MULTIPOLAR MAGNETIC FIELDS. II. FLUX ROPE ERUPTIONS WITH CURRENT SHEETS
	Huang, L 1,2; Yu C(余聪)2,3
刊名	ASTROPHYSICAL JOURNAL
	2014-11-20
卷号	796 期号:1
关键词	instabilities pulsars: general stars: magnetars stars: magnetic field stars: neutron
ISSN号	0004-637X
通讯作者	Huang, L (reprint author), Chinese Acad Sci, Shanghai Astron Observ, Key Lab Res Galaxies & Cosmol, Shanghai 200030, Peoples R China.
产权排序	第三完成单位
英文摘要	We propose a physical mechanism to explain giant flares and radio afterglows in terms of a magnetospheric model containing both a helically twisted flux rope and a current sheet (CS). With the appearance of a CS, we solve a mixed boundary value problem to get the magnetospheric field based on a domain decomposition method. We investigate properties of the equilibrium curve of the flux rope when the CS is present in background multipolar fields. In response to the variations at the magnetar surface, it quasi-statically evolves in stable equilibrium states. The loss of equilibrium occurs at a critical point and, beyond that point, it erupts catastrophically. New features show up when the CS is considered. In particular, we find two kinds of physical behaviors, i.e., catastrophic state transition and catastrophic escape. Magnetic energy would be released during state transitions. This released magnetic energy is sufficient to drive giant flares, and the flux rope would, therefore, go away from the magnetar quasi-statically, which is inconsistent with the radio afterglow. Fortunately, in the latter case, i.e., the catastrophic escape, the flux rope could escape the magnetar and go to infinity in a dynamical way. This is more consistent with radio afterglow observations of giant flares. We find that the minor radius of the flux rope has important implications for its eruption. Flux ropes with larger minor radii are more prone to erupt. We stress that the CS provides an ideal place for magnetic reconnection, which would further enhance the energy release during eruptions.
学科主题	Astronomy & Astrophysics
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	X-RAY PULSAR ; 1998 AUGUST 27 ; MAGNETOSPHERES ; REPEATERS ; RECONNECTION ; SGR-1806-20 ; EVOLUTION ; DYNAMICS
收录类别	SCI
原文出处	http://iopscience.iop.org/article/10.1088/0004-637X/796/1/3/meta
语种	英语
WOS记录号	WOS:000344550300003
内容类型	期刊论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/4569]
专题	云南天文台_大样本恒星演化研究组云南天文台_中国科学院天体结构与演化重点实验室
作者单位	1.Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, China 2.Key Laboratory for the Structure and Evolution of Celestial Object, Chinese Academy of Sciences, Kunming 650011, China 3.Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011, China
推荐引用方式 GB/T 7714	Huang, L,Yu C. MAGNETAR GIANT FLARES IN MULTIPOLAR MAGNETIC FIELDS. II. FLUX ROPE ERUPTIONS WITH CURRENT SHEETS[J]. ASTROPHYSICAL JOURNAL,2014,796(1).
APA	Huang, L,&Yu C.(2014).MAGNETAR GIANT FLARES IN MULTIPOLAR MAGNETIC FIELDS. II. FLUX ROPE ERUPTIONS WITH CURRENT SHEETS.ASTROPHYSICAL JOURNAL,796(1).
MLA	Huang, L,et al."MAGNETAR GIANT FLARES IN MULTIPOLAR MAGNETIC FIELDS. II. FLUX ROPE ERUPTIONS WITH CURRENT SHEETS".ASTROPHYSICAL JOURNAL 796.1(2014).