Surge-like Oscillations above Sunspot Light Bridges Driven by   Magnetoacoustic Shocks

doi:10.3847/1538-4357/aa63e8

CORC > 北京大学 > 地球与空间科学学院

	Surge-like Oscillations above Sunspot Light Bridges Driven by Magnetoacoustic Shocks
	Zhang, Jingwen ; Tian, Hui ; He, Jiansen ; Wang, Linghua
刊名	ASTROPHYSICAL JOURNAL
	2017
关键词	line: profiles Sun: chromosphere Sun: oscillations sunspots Sun: transition region REGION-IMAGING-SPECTROGRAPH HIGH-RESOLUTION OBSERVATIONS TRANSITION-REGION PLASMA EJECTIONS MAGNETIC-FIELDS DYNAMIC FIBRILS FLUX EMERGENCE UMBRAL FLASHES WAVES PROPAGATION
DOI	10.3847/1538-4357/aa63e8
英文摘要	High-resolution observations of the solar chromosphere and transition region often reveal surge-like oscillatory activities above sunspot light bridges (LBs). These oscillations are often interpreted as intermittent plasma jets produced by quasi-periodic magnetic reconnection. We have analyzed the oscillations above an LB in a sunspot using data taken by the Interface Region Imaging Spectrograph. The chromospheric 2796 angstrom. images show surge-like activities above the entire LB at any time, forming an oscillating wall. Within the wall we often see that the core of the Mg. II. k 2796.35 angstrom. line first experiences a large blueshift, and then gradually decreases to zero shift before increasing to a redshift of comparable magnitude. Such a behavior suggests that the oscillations are highly nonlinear and likely related to shocks. In the 1400 angstrom. passband, which samples emission mainly from the Si. IV. ion, the most prominent feature is a bright oscillatory front ahead of the surges. We find a positive correlation between the acceleration and maximum velocity of the moving front, which is consistent with numerical simulations of upward propagating slow-mode shock waves. The Si IV 1402.77 angstrom. line profile is generally enhanced and broadened in the bright front, which might be caused by turbulence generated through compression or by the shocks. These results, together with the fact that the oscillation period stays almost unchanged over a long duration, lead us to propose that the surge-like oscillations above LBs are caused by shocked p-mode waves leaked from the underlying photosphere.; ESA; Norwegian Space Centre; NSFC [41574166, 41574168]; Recruitment Program of Global Experts of China; Max Planck Partner Group program; ISSI Bern; SCI(E); ARTICLE; 1; 838
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/474531]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Zhang, Jingwen,Tian, Hui,He, Jiansen,et al. Surge-like Oscillations above Sunspot Light Bridges Driven by Magnetoacoustic Shocks[J]. ASTROPHYSICAL JOURNAL,2017.
APA	Zhang, Jingwen,Tian, Hui,He, Jiansen,&Wang, Linghua.(2017).Surge-like Oscillations above Sunspot Light Bridges Driven by Magnetoacoustic Shocks.ASTROPHYSICAL JOURNAL.
MLA	Zhang, Jingwen,et al."Surge-like Oscillations above Sunspot Light Bridges Driven by Magnetoacoustic Shocks".ASTROPHYSICAL JOURNAL (2017).