太阳黑子本影振荡的多波段观测  

Multi-wavelength Observations of Umbral Oscillations above a Sunspot

作　　者：李东 LI Dong(Purple Mountain Observatory,Chinese Academy of Sciences,Nanjing 210023)

机构地区：[1]中国科学院紫金山天文台,南京210023

出　　处：《天文学报》2024年第1期76-87,共12页Acta Astronomica Sinica

基　　金：国家自然科学基金项目(11973092);江苏省自然科学基金项目(BK20211402)资助。

摘　　要：基于多波段的观测数据,研究了黑子本影振荡在太阳大气不同高度或温度的振荡特征.目标黑子发生在2017年9月15日,位于活动区12680.多波段的观测数据包括AIA(Atmospheric Imaging Assembly)的极紫外成像及IRIS(Interface Region Imaging Spectrograph)的紫外光谱和成像.在太阳黑子的本影位置,AIA 1700Å光变曲线的振荡周期约为(4.2±0.8)min,而AIA 1600Å、171Å和193Å光变曲线的振荡周期约为(2.8±0.3)min.IRIS的Mg II h和k谱线及远紫外成像(2796Å)都表现为(3.1±0.5)min的准周期振荡,而谱线Si IV 1393.76Å的振荡周期约为(2.9±0.4)min.观测结果说明黑子本影的振荡周期随着太阳大气高度的升高而逐渐减小.较短的周期可认为是3 min振荡,很可能与黑子本影上方的慢磁声波有关,它起源于温度极小区并向上传播到日冕.较长的周期可解释为光球的5 min振荡,与太阳的P模振荡有关.We investigate the umbral oscillation at multi-height solar atmospheres above a sunspot in the active region National Oceanic and Atmospheric Administration(NOAA)12680 on 2017 September 15.In this study,the extreme ultraviolet images were measured by the Atmospheric Imaging Assembly(AIA),while the ultraviolet spectral lines and images were observed by the Interface Region Imaging Spectrograph.At the sunspot umbra,the AIA 1700Åintensity curve shows the primary oscillation with a long period of~(4.2±0.8)minutes,while the intensity curves in AIA 1600Å,171Åand 193Åexhibit an,apparent oscillation with a short period of~(2.8±0.3)minutes.Meanwhile,a short period of~(3.1±0.5)minutes is found in the MgIIh&k lines and the slit-jaw image at 2796Å,a short period of~(2.9±0.4)minutes is detected in the Si IV 1393.76Åline.Our observations suggest that the oscillatory periods at the sunspot umbra decrease with the height of solar outer atmospheres.The short period is roughly equal to 3 minutes,which could be interpreted as the propagating slow magnetoacoustic wave above the sunspot umbra,and it might originate from the temperature minimum region and then propagate up to the corona.While the long period is close to 5 minutes oscillation in the photosphere,which might be regarded as the solar P-mode wave.

关 键 词：太阳黑子 太阳:大气 太阳:振荡 磁流体力学 波动 

分 类 号：P182[天文地球—天文学]