论文标题
阿尔玛在3毫米处检测到的安静阳光下的瞬态亮光
Transient brightenings in the quiet Sun detected by ALMA at 3 mm
论文作者
论文摘要
使用ALMA观察，我们在3毫米处的安静太阳能球中进行了首次进行瞬态亮丽（即弱的，小规模的能量释放发作）的系统调查。我们的数据集包括六个87''x 87''的图像，该区域的安静太阳以2秒为单位的几个ArcSec获得了斜面分辨率。在我们去除P模式振荡的效果后，瞬态亮丽被检测到高于平均强度高于平均强度的弱增强。在同一区域对使用大气成像组件获得的同时304和1600Å数据进行了类似的分析。我们检测到184 3毫米瞬态亮点事件，其亮度温度从70 K到$ \ sim 7200-7450 $ K以上的亮度温度从70 K到超过500 k。它们的平均持续时间和最大面积分别为51.1 s和12.3 mm $ $^2 $，而不是在网络边界而不是细胞室内的网络界面。这两个参数均表现出幂律行为，指数分别为2.35和2.71。只有一小部分的ALMA事件具有304或1600Å的对应物，但是这些事件的特性与普通人群的特性没有显着差异，除了它们缺乏低端能量值。 ALMA瞬态亮片的总热能在$ 1.5 \ times 10^{24} $和$ 9.9 \ times 10^{25} $ erg及其频率分布与能量的频率是索引为1.67的功率定律。我们发现，ALMA事件提供的每单位区域的功率仅占色球辐射损失的1％（10 \％的冠状动脉损失）。因此，他们的能源预算不足以满足太阳大气上层上层加热的要求，即使我们使用最少的限制性标准来检测瞬态亮度，这一结论也不会改变。
Using ALMA observations, we performed the first systematic survey for transient brightenings (i.e. weak, small-scale episodes of energy release) in the quiet solar chromosphere at 3 mm. Our dataset included images of six 87'' x 87'' regions of the quiet Sun obtained with angular resolution of a few arcsec at a cadence of 2 s. The transient brightenings were detected as weak enhancements above the average intensity after we removed the effect of the p-mode oscillations. A similar analysis, over the same regions, was performed for simultaneous 304 and 1600 Å data obtained with the Atmospheric Imaging Assembly. We detected 184 3 mm transient brightening events with brightness temperatures from 70 K to more than 500 K above backgrounds of $\sim 7200-7450$ K. Their mean duration and maximum area were 51.1 s and 12.3 Mm$^2$, respectively, with a weak preference of appearing at network boundaries rather than in cell interiors. Both parameters exhibited power-law behavior with indices of 2.35 and 2.71, respectively. Only a small fraction of ALMA events had either 304 or 1600 Å counterparts but the properties of these events were not significantly different from those of the general population except that they lacked their low-end energy values. The total thermal energies of the ALMA transient brightenings were between $1.5 \times 10^{24}$ and $9.9 \times 10^{25}$ erg and their frequency distribution versus energy was a power law with an index of 1.67. We found that the power per unit area provided by the ALMA events could account for only 1\% of the chromospheric radiative losses (10\% of the coronal ones). Therefore, their energy budget falls short of meeting the requirements for the heating of the upper layers of the solar atmosphere and this conclusion does not change even if we use the least restrictive criteria possible for the detection of transient brightenings.
