The perplexing mystery of what maintains the solar coronal temperature at about a million K, while the visible disc of the Sun is only at 5800 K, has been a long standing problem in solar physics. A recent study by Mondal(2020) has provided the first evidence for the presence of numerous ubiquitous impulsive emissions at low radio frequencies from the quiet sun regions, which could hold the key to solving this mystery. These features occur at rates of about five hundred events per minute, and their strength is only a few percent of the background steady emission. One of the next steps for exploring the feasibility of this resolution to the coronal heating problem is to understand the morphology of these emissions. To meet this objective we have developed a technique based on an unsupervised machine learning approach for characterising the morphology of these impulsive emissions. Here we present the results of application of this technique to over 8000 images spanning 70 minutes of data in which about 34,500 features could robustly be characterised as 2D elliptical Gaussians.
翻译:太阳日冕温度维持在大约100万K,而太阳可见盘仅处于5800K,这是太阳物理学中长期存在的一个问题。Mondal(2020)最近的一项研究提供了第一个证据,证明在低射频中存在来自静悄悄太阳区域的无数无处不在的冲动性排放,这可以作为解决这一神秘问题的关键。这些特征以每分钟大约500场事件的速度发生,其强度仅占背景稳定排放的一小部分。探索这一解决方案对日冕供热问题的可行性的下一步之一是了解这些排放的形态。为了实现这一目标,我们开发了一种技术,以不受监督的机器学习方法来描述这些无线状排放的形态。我们在这里介绍了这种技术应用到8000多幅覆盖70分钟的数据的图像的结果,其中大约34,500个特征可以有力地描述为2D高斯人。