Life, Energy, Dynamics and Dark Matter - Exploring X-rays from the Outer Planets

外太阳系确实是一个充满奇迹的地方：壮观的极光显示，能量如此之高，以至于可以为人类文明提供动力；拥有全球地下海水海洋的卫星--这可能是生命的完美环境；磁气泡(“磁层”)，这是太阳系中最大的相干结构；充满能量如此之高的粒子的强烈辐射带，以至于它们以接近光速的速度旅行；标志性的闪闪发光的光环，延伸到地球直径的20倍，环绕其气体主机。宇宙是如何创造这些奇迹的，以及是什么过程支配着它们，这是太阳系科学和这项研究的核心。历史上，NASA和ESA的旗舰X射线天文台Chandra和XMM-牛顿一直被广泛用于研究能量超乎想象的或大的(黑洞、中子星或在星系之间流动的气体)。然而，X射线天文台也提供了对行星体的宝贵和未得到充分利用的见解。我的研究旨在确保我们充分利用各种不同的X射线能力来研究外行星。X射线荧光是一个产生原子元素指纹特征的过程。因此，它是确定某物由什么原子组成的极佳工具。在地球上，从判断艺术品是否为赝品，到识别油漆中的铅、食品中的氯和化妆品中的金属，X射线荧光被用于各种用途。通过ERF，我将研究木星的卫星木卫一、木卫二、木卫三和木卫四的X射线荧光。这将识别木卫二冰面上最常见的元素，区分木卫二海洋中的不同盐分，以确定那里存在潜在生命的条件。木卫二在木星磁层内绕木星运行。这个围绕行星的巨大磁洞是木星快速自转、强磁场和木星卫星木卫一上火山不断注入的等离子体(电离粒子)共同作用的结果。等离子体占观测宇宙的99%。因此，了解是什么过程支配着等离子体的行为，对于理解我们在宇宙中观察到的物质至关重要。我将使用X射线观测和行星轨道上航天器的测量，以几种方式研究这些基本的等离子体过程：1.探索木星跳舞的极光显示，以探测粒子的流动和控制它们的过程2。分析强辐射带的X射线图像，以确定它们如何随时间变化，以及什么过程触发这些变化3。计算木星、土星、天王星和海王星磁层与太阳风之间的边界上的X射线辐射，为拍摄这一边界的视频，研究每颗行星与其周围空间环境(太阳风)之间的全球关系奠定了基础。对系外行星的研究表明，冰巨星是宇宙中最常见的行星类型之一。然而，我们当地的冰雪巨星天王星和海王星却知之甚少。20世纪80年代旅行者号航天器的快速飞行是我们对这两颗行星的唯一一次访问。在没有任何近期访问这些行星的计划的情况下，我们不得不通过地球上的望远镜来研究它们。我将寻求获得天王星新的X射线观测时间。这将使我们能够探索之前观测到的许多令人兴奋的线索，测试是否存在闪闪发光的X射线极光、光环的X射线辉光和来自大气层的潜在荧光。通过这些不同的项目，研究计划将在外太阳系X射线观测的使用方面迎来一场革命，建立新的研究领域，并利用X射线波段提供对太阳系外部神秘而神奇的世界的独特见解。

The outer solar system is truly a place of wonders: spectacular auroral displays, so energetic that they could power Human civilization; moons with global sub-surface water oceans - potentially perfect environments for life; magnetic bubbles ('magnetospheres') that are the largest coherent structures in the solar system; intense radiation belts filled with particles so energetic that they travel at close to the speed of light; iconic glistening rings extending 20 times the diameter of Earth into space to encircle their gaseous hosts. How the cosmos creates these marvels and what processes govern them is at the heart of solar system science and this research.Historically, NASA and ESA's flagship X-ray observatories, Chandra and XMM-Newton, have been widely used to study the unimaginably energetic or large (black holes, neutron stars or the gas that flows between galaxies). However, X-ray observatories also provide invaluable and under-utilised insights into planetary bodies. My research aims to ensure that we fully utilise the diverse range of X-ray capabilities to study the outer planets.X-rays fluorescence is a process that produces 'fingerprint' signatures of atomic elements. Consequently, it is excellent for determining what atomic elements something is composed of. On Earth, X-ray fluorescence is used for everything from determining whether a piece of art is fake, to identifying lead in paint, chlorine in food and metals in cosmetics. Through the ERF, I will study X-ray fluorescence from Jupiter's moons Io, Europa, Ganymede and Callisto. This will identify which elements are most common on their icy surfaces, distinguishing between different salts in Europa's ocean to identify what conditions are available there for potential life.Europa orbits Jupiter within Jupiter's magnetosphere. This vast magnetic cavity around the planet forms through the combination of Jupiter's rapid-rotation, strong magnetic field, and the constant injections of plasma (ionised particles) from the volcanoes on Jupiter's moon, Io. Plasma makes up 99% of the observed Universe. Understanding what processes govern the behaviours of plasmas is therefore critical to understanding the matter we observe across the cosmos. I will use X-ray observations in tandem with measurements by spacecraft in orbit at the planets to study these fundamental plasma processes in several ways: 1. exploring Jupiter's dancing auroral displays to probe the flows of particles and the processes that control them2. analysing X-ray images of the intense radiation belts to determine how they change over time and what processes trigger these changes3. calculating the X-ray emissions along the boundary between the magnetospheres of Jupiter, Saturn, Uranus and Neptune and the solar wind, laying foundations to take videos of this boundary, to study the global relationship between each planet and its surrounding space envrionment (the solar wind).The study of exoplanets has shown that Ice Giants are amongst the most common type of planet in the Universe. However, our local Ice Giants, Uranus and Neptune, are very poorly understood. The rapid flybys of the Voyager spacecraft in the 1980s are the only visit we have ever made to either planet. Without any near-term plans to visit these planets, we have to study them through telescopes at Earth. I will seek to acquire new X-ray observing time for Uranus. This will enable us to explore many of the exciting hints suggested by previous observations, testing for the presence of: sparkling X-ray aurorae, the X-ray glow of the rings and potential fluorescence from the atmosphere.Through these diverse projects, the research programme will usher in a revolution in the uses of X-ray observations for the outer solar system, founding new research fields and leveraging the X-ray waveband to provide unique insights into the mysterious and wonderous worlds in the outer regions of our solar system.