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arXiv 2102.08678astro-ph.SR
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在太阳平静区和活动区用声波对色球加热的IRIS观测

IRIS observations of chromospheric heating by acoustic waves in solar quiet and active regions

V. Abbasvand, M. Sobotka, M. Švanda, P. Heinzel, W. Liu, L. Mravcová

摘要:

目的:为了研究声波和磁声波对太阳色球磁区和磁区的加热,将来自强色球线观测的沉积声能通量与总积分辐射损失进行比较。方法:用界面区成像光谱仪(IRIS)在Mg Ⅱ的K线和H线上观测了23个静日区和弱斑区。沉积的声能通量来自多普勒速度观测在两个不同的几何高度对应的中间和上部色球。一组缩放的非局部热力学平衡一维流体静力学半经验模型(通过拟合合成观测线轮廓获得)被施加到计算辐射损失。用小波分析方法研究了观测波的特征。结果:观察到的波以超声速向上传播。在安静的色球层中,沉积的声通量足以平衡辐射损失,并保持所研究的层中的半经验温度。在色球活动区,声能通量对辐射损失的贡献仅为10 - 30%。结论:声波和磁声波在色球加热中起着重要的作用,它们的能量主要集中在色球层。声波补偿了安静区域中色球辐射损失的很大一部分。在活跃区,它们的贡献太小,无法平衡辐射损失,色球层必须通过其他机制加热。

英文摘要:

Aims: To study the heating of solar chromospheric magnetic and nonmagnetic regions by acoustic and magnetoacoustic waves, the deposited acoustic-energy flux derived from observations of strong chromospheric lines is compared with the total integrated radiative losses. Methods: A set of 23 quiet-Sun and weak-plage regions were observed in the Mg II k and h lines with the Interface Region Imaging Spectrograph (IRIS). The deposited acoustic-energy flux was derived from Doppler velocities observed at two different geometrical heights corresponding to the middle and upper chromosphere. A set of scaled nonlocal thermodynamic equilibrium 1D hydrostatic semi-empirical models (obtained by fitting synthetic to observed line profiles) was applied to compute the radiative losses. The characteristics of observed waves were studied by means of a wavelet analysis. Results: Observed waves propagate upward at supersonic speed. In the quiet chromosphere, the deposited acoustic flux is sufficient to balance the radiative losses and maintain the semi-empirical temperatures in the layers under study. In the active-region chromosphere, the comparison shows that the contribution of acoustic-energy flux to the radiative losses is only 10 - 30 %. Conclusions: Acoustic and magnetoacoustic waves play an important role in the chromospheric heating, depositing a main part of their energy in the chromosphere. Acoustic waves compensate for a substantial fraction of the chromospheric radiative losses in quiet regions. In active regions, their contribution is too small to balance the radiative losses and the chromosphere has to be heated by other mechanisms.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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