Determining the fundamental nature of the solar atmosphere: applying Bayesian analysis methods to Hinode observations

说太阳很重要其实是轻描淡写的--我们之所以在这里，是因为距离我们最近的恒星提供了地球上生命所需的光和热。此时，我们正处于日地研究的黄金时代，几个主要的卫星任务彻底改变了我们对从太阳到地球的能量流动的理解。特别是，2006年底，日本、英国和美国联合发射了一颗名为Hinode(日语中日出的意思)的卫星。Hinode将使用一系列仪器，在光学、极端紫外线和X射线波长下观察来自太阳的光，研究太阳磁场和其外层大气之间的密切关系。太阳物理学中剩下的一个悬而未决的问题是，为什么外层大气的温度从光球层(可见光的发源地)的5780K上升到最外面的日冕部分的数百万度。显然，当你离开一个热源(在这种情况下，是太阳核心的核反应产生的能量)时，温度应该会下降。一些额外的加热一定是将额外的能量直接倾倒到日冕中，从而造成了这种违反直觉的温度上升。已经提出了几种机制，它们都以太阳磁场为中心。然而，关于如何解决这一“日冕供暖问题”的具体细节，目前还没有科学上的共识。特别值得一提的是，从日冕发出的辐射有很大一部分集中在定义明确的环状拱门上。这些环路是大气层的基本结构元素，当磁场在恒星表面升起时，它们与磁场重合，沿着恒星的长度‘捕获’带电气体(等离子体)。这项申请中提出的研究试图以前所未有的方式使用Hinode来探测日冕。这项工作的一部分将涉及探测和测量“磁声波”(称为磁声振荡)，因为它们沿着环路传播，携带能量穿过太阳大气。此外，通过使用太阳光谱技术，我们将远程测量环路上的温度和密度，以帮助我们进一步了解日冕的性质，以及这些额外的能量可能被储存在哪里。为了全面检查我们的观察，我们将使用一套称为贝叶斯分析方法的统计工具-这些技术允许我们在调查中添加尽可能多的先验信息或关于环路的知识。这将是太阳物理学的一种新方法，帮助我们将我们的理论模型与这些最新的卫星观测进行比较。

To say the Sun is important really is an understatement- we are here because our closest star provides the necessary light and heat required for life on Earth. We are in a golden era of solar-terrestrial research at this time with several major satellite missions revolutionising our understanding of the flow of energy from the Sun to the Earth. In particular, a joint Japanese, British and American satellite called Hinode (meaning 'sunrise' in Japanese) was launched in late 2006. Using a combination of instruments that observe the light from the Sun in optical, Extreme Ultraviolet and X-ray wavelengths, Hinode will study the intimate relationship between the Sun's magnetic field and its outer atmospheric layers. One of the remaining unresolved questions in solar physics is why the temperature of this outer atmosphere rises from 5780 K at the photosphere (where the visible light originates) to millions degrees in the outermost parts- the corona. Clearly as you move away from a heat source (in this case the energy generated by nuclear reactions at the core of the Sun), the temperature should fall away. Some additional heating must be dumping extra energy directly into the corona to create this counter-intuitive temperature rise. Several mechanisms have been suggested which are all centred around the Sun's magnetic field. However, there is as yet no scientific consensus on the specific details on how this 'coronal heating problem' can be solved. In particular, a significant proportion of the radiation emitted from the solar corona is concentrated along well-defined loop-like arches. These loops are the basic structural elements of the atmosphere and coincide with the magnetic field as it rises out though the surface of the star, 'trapping' the electrified gases (the plasma) along its length. The research proposed in this application seeks to use Hinode to probe the corona like never before. Part of the work will deal with detecting and measuring 'magnetic sound waves' (termed magnetoacoustic oscillations) as they travel along loops, carrying energy through the solar atmosphere. Also, by using techniques in solar spectroscopy, we will measure remotely the temperature and density along loops to help us further understand the nature of the corona and where this extra energy could be being deposited. To fully examine our observations, we will use a set of statistical tools called Bayesian analysis methods- these techniques allow us to add into our investigations as much prior information or knowledge of the loops as possible. This will be a new way in Solar Physics to help us compare our theoretical models with these latest satellite observations.