论文标题
CYRA和IRIS检测到的黑子的多普勒移位振荡
Doppler shift oscillations of a sunspot detected by CYRA and IRIS
论文作者
论文摘要
语境。在太阳红外光谱中，一氧化碳（CO）分子线通常用于研究太阳大气中的冷心的动态行为，即Sunspot振荡，尤其是在黑子蒙布特（Sunspot Umbra）。目标。我们研究了通过低温红外光谱仪（CYRA）测量的CO 7-6 R67和3-2 R14线的多普勒速度的Sunspot振荡，以及由界面区域成像仪（IRIS）检测到的MG II K线的线曲线。方法。将单个高斯函数应用于每个CO线曲线以提取线移，而MONS分析方法则用于MG II K线。然后可以在多普勒速度的时距离图像中找到黑子振荡，而在小波功率谱中确定了黑子umbra处的准周期性。最后，使用互相关方法来分析不同大气水平之间的相位关系。结果。在黑子象形下，在光电指控中形成的CO 7-6 R67线的多普勒速度范围内检测到大约5分钟的周期性，而在CO 3-2 R14和MG II K线的多普勒速度上发现了大约3分钟的周期性，该速度在上层照相机上均构成了高度照相或温度最低温度最低温度最低温度的chrom。在强CO 3-2 R14线和Mg II K线之间测量了约2分钟的时间延迟。结论。基于Cyra和Iris的光谱观测结果，可以在多普勒偏移中空间分辨出3分钟的黑子振荡。它可能来自上部光球或温度最小区域，然后传播到色球，这可能被视为传播慢速磁声波。
Context. The carbon monoxide (CO) molecular line at around 46655 A in solar infrared spectra is often used to investigate the dynamic behavior of the cold heart of the solar atmosphere, i.e., sunspot oscillation, especially at the sunspot umbra. Aims. We investigated sunspot oscillation at Doppler velocities of the CO 7-6 R67 and 3-2 R14 lines that were measured by the Cryogenic Infrared Spectrograph (CYRA), as well as the line profile of Mg II k line that was detected by the Interface Region Imaging Spectrograph (IRIS). Methods. A single Gaussian function is applied to each CO line profile to extract the line shift, while the moment analysis method is used for the Mg II k line. Then the sunspot oscillation can be found in the time-distance image of Doppler velocities, and the quasi-periodicity at the sunspot umbra are determined from the wavelet power spectrum. Finally, the cross-correlation method is used to analyze the phase relation between different atmospheric levels. Results. At the sunspot umbra, a periodicity of roughly 5 min is detected at the Doppler velocity range of the CO 7-6 R67 line that formed in the photosphere, while a periodicity of around 3 min is discovered at the Doppler velocities of CO 3-2 R14 and Mg II k lines that formed in the upper photosphere or the temperature minimum region and the chromosphere. A time delay of about 2 min is measured between the strong CO 3-2 R14 line and the Mg II k line. Conclusions. Based on the spectroscopic observations from the CYRA and IRIS, the 3 min sunspot oscillation can be spatially resolved in the Doppler shifts. It may come from the upper photosphere or the temperature minimum region and then propagate to the chromosphere, which might be regarded as a propagating slow magnetoacoustic wave.
