太阳活动区一次微小微耀斑的NuSTAR观测
NuSTAR Observation of a Minuscule Microflare in a Solar Active Region
摘要：
我们提出了一个最弱的活动区（AR）微耀斑的X射线成像光谱学研究。微耀斑发生在2018年9月9日的$\sim$ 11：04 UT，我们使用核光谱望远镜ARray（NuSTAR）和太阳动力学天文台的大气成像组件（SDO/AIA）对其进行了研究。在2.5-7 keV能量范围内，用NuSTAR和94 $\unicode{x212B}$ SDO/AIA通道较热分量的Fe XVIII发射观测到了清晰的微耀斑。我们估计该事件比GOES A级微耀斑低三个数量级，能量为1.1 $\times$ 10 $^{26}$ erg。其温度达到6.7 MK，发射测量值为8.0 $\times$ 10 $^{43}$ cm $^{-3}$。未检测到非热发射，但我们确定了此类发射的上限。我们提出了最低的热能估计AR微耀斑在文献中，这是在什么仍然被认为是一个X射线微耀斑的下限。
英文摘要：
We present X-ray imaging spectroscopy of one of the weakest active region (AR) microflares ever studied. The microflare occurred at $\sim$11:04 UT on 2018 September 9 and we studied it using the Nuclear Spectroscopic Telescope ARray (NuSTAR) and the Solar Dynamic Observatory's Atmospheric Imaging Assembly (SDO/AIA). The microflare is observed clearly in 2.5-7 keV with NuSTAR and in Fe XVIII emission derived from the hotter component of the 94 $\unicode{x212B}$ SDO/AIA channel. We estimate the event to be three orders of magnitude lower than a GOES A class microflare with an energy of 1.1$\times$10$^{26}$ erg. It reaches temperatures of 6.7 MK with an emission measure of 8.0$\times$10$^{43}$ cm$^{-3}$. Non-thermal emission is not detected but we instead determine upper limits to such emission. We present the lowest thermal energy estimate for an AR microflare in literature, which is at the lower limits of what is still considered an X-ray microflare.
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。
