论文标题
太阳活动区域周围的平坦磁场中缺失的凉爽电晕
The Missing Cool Corona in the Flat Magnetic Field around Solar Active Regions
论文作者
论文摘要
SDO/AIA在几个EUV频段中图像整个太阳能磁盘对一个或多个特定温度的冠状血浆排放敏感。我们观察到，当隔离的活动区域（AR）位于磁盘上时，一些冠状EUV通道中的全盘图像显示了AR的郊区，作为AR周围的深色护城河。在这里，我们提出了七个特定示例，这些示例是从磁盘上只有一个AR的时间段选择的。从视觉上讲，我们观察到护城河在AIA 171 Angstrom带中是最突出的，该带对log10 t = 5.8时血浆发射的敏感性最高。通过检查从六个AIA EUV通道中发现的一维发射量度测量温度分布，我们发现在大多数情况下，护城河的强度在温度范围log10 t〜5.7-6.2上最为抑郁。我们认为存在深色护城河，因为从AR上溅出的强磁场的压力会向下压在下面的磁环上，将这些环的压扁 - 以及AR自身自身的循环在护城河上的最低循环 - 至低海拔。根据AntioChos＆Noci（1986）的说法，这些循环通常会散发出171埃埃斯特罗姆排放的大部分，仅限于表面上方的高度，无法在其中持续171个埃埃夫斯特罗姆发光等离子体，而较热的EUV等离子体则在高温的EUV等离子体中持续过高，在上层高的较高的较高的较高的较高的较高的较高的coronal-roops中。这可能解释了ARS周围的低孔 - 温度深色护城河。
SDO/AIA images the full solar disk in several EUV bands that are each sensitive to coronal plasma emissions of one or more specific temperatures. We observe that when isolated active regions (ARs) are on the disk, full-disk images in some of the coronal EUV channels show the outskirts of the AR as a dark moat surrounding the AR. Here we present seven specific examples, selected from time periods when there was only a single AR present on the disk. Visually, we observe the moat to be most prominent in the AIA 171 Angstrom band, which has the most sensitivity to emission from plasma at log10 T = 5.8. By examining the 1D line-of-sight emission measure temperature distribution found from six AIA EUV channels, we find the intensity of the moat to be most depressed over the temperature range log10 T ~ 5.7 - 6.2 for most of the cases. We argue that the dark moat exists because the pressure from the strong magnetic field that splays out from the AR presses down on underlying magnetic loops, flattening those loops -- along with the lowest of the AR's own loops over the moat -- to a low altitude. Those loops, which would normally emit the bulk of the 171 Angstrom emission, are restricted to heights above the surface that are too low to have 171 Angstrom-emitting plasmas sustained in them, according to Antiochos & Noci (1986), while hotter EUV-emitting plasmas are sustained in the overlying higher-altitude long AR-rooted coronal loops. This potentially explains the low-coronal-temperature dark moats surrounding the ARs.
