Warwick Astronomy & Astrophysics Consolidated Grant 2023-2026

恒星、行星和星系是如何形成的？它们是如何进化的，又是如何死亡的？华威大学（University of Warwick）的天文学和天体物理学小组通过大型和小型望远镜的观测以及物理驱动的计算模型来研究诸如此类的问题。光学望远镜在天文学中的使用可以追溯到400多年前的伽利略时代，但我们现在正处于一个新的伽利略发现时代，2015年才首次探测到引力波。GWs提供了一种完全不同的宇宙观，深入到最极端事件的核心，即难以想象的密集恒星螺旋聚集在一起，并在合并前的最后时刻，与整个可观测宇宙的其余部分的功率输出相媲美。GW望远镜可以同时“看到”几乎所有的地方，但相当于非常模糊的视觉。为了精确定位光源，我们需要用电磁（EM）来观察它们，即使用光学、无线电和x射线望远镜，但即使这样也很困难，因为你必须知道首先要看哪里。在沃里克大学，我们正在研究一种叫做GOTO的望远镜。从欧洲和澳大利亚的站点，GOTO被设计为视野的广度和速度，在几分钟内追踪宇宙中最快和最猛烈的事件。在我们的银河系中，许多强度较小但持续时间较长的物体发出的gww离地球更近。我们开始从EM观测中发现系统，这些系统也可以从太空中探测到GW源。这些都是奇异的来源：一个由两颗恒星组成，每颗恒星的大小都与地球相当，但质量是地球的10万倍，它们在5分钟多一点的时间内相互绕一圈。我们将使用安装在大型光学望远镜上的专业高速摄像机来研究它们，以探索它们是如何进化的，这是了解它们有多少以及它们是如何形成的重要一步。引力波为我们提供了观察宇宙的新视角，但新的仪器和技术几乎做着同样的事情。1995年，第一颗系外行星被发现，这是通过对一种叫做光谱学的古老天文学工具的特别敏感的应用。从那时起，成千上万的行星在令人眼花缭乱的各种系统中被发现，其中许多与我们的太阳系非常不同。在华威大学，我们长期以来一直在利用地球和太空望远镜发现系外行星，并将在这次拨款中这样做，以了解当行星靠近其主星时可能破坏或侵蚀行星的过程。许多已知的系外行星离它们的宿主恒星很近，但这在一定程度上取决于我们发现它们的方式，所以我们研究的另一个方向是将行星探测推向更宽的轨道，更接近我们太阳系的轨道。沃里克对欧空局领导的一项名为PLATO的新太空任务有着浓厚的兴趣，该任务将为这项工作提供巨大的推动力。PLATO拥有广阔的视野，可以捕捉到围绕最亮恒星运行的行星。这些都是关键目标，因为它们离我们很近，但最重要的是，它们使光谱学的应用更具挑战性，足以让我们探测到行星大气的组成。地球和太阳系的其他行星是由年轻的太阳周围的物质盘形成的，这些物质盘作为行星本身存在，但也有彗星、小行星和尘埃形式的“碎片”。我们的目标是在其他恒星周围找到类似结构的证据，特别是从它们散射星光的尘埃中找到证据。这些物质可以在恒星几十亿年的生命周期中存活下来，直到只剩下一个被称为白矮星的炽热致密的残骸。白矮星的形成应该“彻底清洁”恒星附近的环境，然而值得注意的是，我们已经发现了许多行星碎片的例子，在我们的研究中，我们的目标是找出这是如何做到的。在恒星演化过程中还有许多其他的白矮星，我们将使用新一代的纤维馈送光谱仪来绘制它们的地图，这种光谱仪一次可以捕捉1000个物体。

How do stars, planets and galaxies form? How do they evolve, how do they die? The Astronomy and Astrophysics group at the University of Warwick studies questions such as these through observations on telescopes, both large and small, and through physics-driven computational modelling. The use of optical telescopes in astronomy dates back over 400 years to Galileo, but we are now in a new Galilean era of discovery with the first detection of gravitational waves (GWs) only made in 2015. GWs provide a completely different view of the universe, delving to the heart of the most extreme events known as unimaginably dense stars spiral together, and, in their last moments before merging, rival the power output of the rest of the entire observable universe. GW telescopes can "see" almost everywhere at once, but have the equivalent of very blurred vision. To pinpoint sources, we need to see them electromagnetically (EM), i.e. with optical, radio and x-ray telescopes, but even that is difficult because you have to know where to look first. At Warwick we are working on a telescope called GOTO to do just this. From sites in Europe and Australia, GOTO is designed for breadth of vision and speed, to chase the universe's fastest and most violent events within minutes of their detection. Many less powerful, but longer lasting objects emit GWs much closer to Earth within our own galaxy, the Milky Way. We are starting to find systems from EM observations that will also be detectable as GW sources from space. These are exotic sources: one consists of two stars, each the size of the Earth but 100,000 times more massive, that circle each other in a little over five minutes. We will apply specialist high-speed cameras to their study, mounted on large optical telescopes, to probe how they evolve and important step in understanding how many of them there are, and how they came to be. Gravitational waves have given us new eyes on the universe, but new instruments and techniques do almost the same thing. In 1995 the first exoplanet was found through a particularly sensitive application of an old tool of astronomy called spectroscopy. Since then thousands of planets have been found in a bewildering variety of systems, many very different from our Solar System. At Warwick we have long pursued the discovery of exoplanets using both telescopes on Earth and in space, and will do so in this grant in order to understand processes that can destroy or erode planets when they are close to their host stars. Many known exoplanets are close to their host stars, but that is in part due to how we find them, so another strand of our research aims to push planetary detection to wider orbits, closer to those of our Solar system. Warwick has a strong interest in a new ESA-led space mission called PLATO which will provide a dramatic boost to this work. PLATO has a large field of view to allow it to pick up planets orbiting the brightest stars. These are key targets as they are close by, but above all they allow even more challenging application of spectroscopy, enough to allow us to probe the very composition of the planetary atmospheres. Earth and the other planets of the Solar system formed from a disk of material around the young Sun that lives on as the planets themselves but also "debris" in the form of comets, asteroids and dust. We aim to find evidence for similar structures around other stars, in particular from their dust as it scatters starlight. Such material can survive the several billion year lifetime of the star until just a hot dense remnant called a white dwarf remains. The formation of a white dwarf should "deep clean" the environment close to the star, and yet remarkably we have found many example of the planetary debris, and within our research we aim to find out how this can be. There are many other white dwarfs left from stellar evolution which we will map using a new generation of fibre-fed spectrographs that capture objects, 1000 at a time.