亚太赫兹太阳活动周期：从SST和ALMA导出的极区和赤道半径
The subterahertz solar cycle: Polar and equatorial radii derived from SST and ALMA
摘要：
在亚太赫兹频率下，毫米和亚毫米波长--在太阳半径以及太阳大气的其他参数的测量方面存在差距。随着观测波长的变化，半径也会变化，因为主导电磁辐射的高度是在太阳大气层的不同高度产生的。此外，整个长时间序列的半径变化表明太阳大气的变化可能与太阳周期有关。因此，太阳半径是一个重要的参数，太阳大气模型的校准，使更好地了解大气结构。在这项工作中，我们使用的数据从太阳亚毫米波望远镜（SST）和阿塔卡马大型毫米/亚毫米阵列（ALMA），在100，212，230和405 GHz的频率，测量赤道和极地半径的太阳。从SST广泛的数据测量的半径与文献中的半径与频率的趋势一致。从ALMA地图在230 GHz的半径也同意的半径与频率的趋势，而100 GHz的半径略高于其他作者报告的值。此外，我们分析了多年来的赤道和极地半径的行为，通过确定太阳活动和亚太赫兹半径时间序列在212和405 GHz（SST）之间的相关系数。在13年的SST导出的半径的变化相关的太阳活动时，考虑到赤道地区的太阳大气，并考虑到极地地区的太阳活动。100和230 GHz的ALMA导出的半径时间序列显示出与SST非常相似的行为。
英文摘要：
At subterahertz frequencies -- i.e., millimeter and submillimeter wavelengths -- there is a gap of measurements of the solar radius as well as other parameters of the solar atmosphere. As the observational wavelength changes, the radius varies because the altitude of the dominant electromagnetic radiation is produced at different heights in the solar atmosphere. Moreover, radius variations throughout long time series are indicative of changes in the solar atmosphere that may be related to the solar cycle. Therefore, the solar radius is an important parameter for the calibration of solar atmospheric models enabling a better understanding of the atmospheric structure. In this work we use data from the Solar Submillimeter-wave Telescope (SST) and from the Atacama Large Millimeter/submillimeter Array (ALMA), at the frequencies of 100, 212, 230, and 405 GHz, to measure the equatorial and polar radii of the Sun. The radii measured with extensive data from the SST agree with the radius-vs-frequency trend present in the literature. The radii derived from ALMA maps at 230 GHz also agree with the radius-vs-frequency trend, whereas the 100-GHz radii are slightly above the values reported by other authors. In addition, we analyze the equatorial and polar radius behavior over the years, by determining the correlation coefficient between solar activity and subterahertz radii time series at 212 and 405 GHz (SST). The variation of the SST-derived radii over 13 years are correlated to the solar activity when considering equatorial regions of the solar atmosphere, and anticorrelated when considering polar regions. The ALMA derived radii time series for 100 and 230 GHz show very similar behaviors with those of SST.
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。
