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PATT travel support for Bristol Astrophysics and Planetary Studies

PATT 对布里斯托尔天体物理学和行星研究的旅行支持

基本信息

批准号：
ST/M00208X/1
负责人：
Mark Birkinshaw
金额：
$ 1.29万
依托单位：
University of Bristol
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2014
资助国家：
英国
起止时间：
2014 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=ST%2FM00208X%2F1
关键词：
PATT travel support Bristol Astrophysics

项目摘要

The Bristol Astrophysics and Planetary Physics groups work on programmes that require careful observations to be made using the world's largest telescopes. This proposal requests two years of funding for travel to those telescopes, to allow observing on projects that cannot be run remotely.In studies of the microwave background radiation, the left-over radiation from the Big Bang, it is important to remove contamination from foreground sources of emission that confuse our measurements of the background itself. Removal of this contamination requires sensitive observations of the radio environments of our target fields using large radio telescopes. Many of the effects we are looking for relate to "shadows" cast on the background radiation by the gas in clusters of galaxies. We also need to study clusters with optical and infra-red telescopes, to measure cluster masses, and so gain insights into how clusters form and change over the history of the Universe.Some of these contaminating radio sources lie within the clusters, and these "active galaxies" which host super-massive black holes in their nuclei, are another subject of our research. We study the physics of these objects mostly using orbiting X-ray telescopes, but imaging at radio, infra-red, and optical bands is also essential. Here again we use large ground-based telescopes, particularly the JVLA in the USA, the ATCA in Australia, and ESO's large telescopes in Chile. A major aim of this work is to understand how active galaxies pump energy into gas in the Universe, helping to keep the gas between the galaxies hot, and so a powerful source of X-rays.Small-scale models of these active galaxies can be found in our own Galaxy, in black hole systems with masses a few times the mass of the Sun. Work on these systems uses similar techniques as work on the far heavier black holes in active galaxies, but with the need to observe frequently and repeatedly, to follow their rapid changes in brightness and structure. From such information we can discover how matter behaves near black holes.A unifying thread of our work is investigating how structure in the Universe forms and changes with time. A large fraction of our observing is dedicated to finding and characterising the earliest galaxies and clusters, and then seeing how young objects differ from their older counterparts that lie close to our Galaxy. Again we use a wide range of telescope for this work, from optical telescopes in Chile to radio telescopes in Australia and the USA, looking at the stars and the gas between them.Nearby galaxies can not only be studied in more detail than distant ones, but we can also look at smaller objects which would be too faint to see if they were further away. It is particularly interesting to us to investigate the lowest-mass galaxies, which are the most common, but have properties that are poorly understood and rather different from the larger objects. These small galaxies are thought to be the building blocks of larger galaxies.We also study our own Galaxy, looking at the gas between the stars which has been heated by supernovae or young stars, and at the dense lumps of gas that emit coherent (maser) radiation - which is extremely bright and variable with time. Gas motions tell us about how the Galaxy recycles gas from stars, and can be used to measure the distances across the Galaxy.Finally, we also seek to investigate the atmospheres of planets and large satellites in our own Solar System. Atmosphere formation and evolution can be followed by detailed spectroscopy, which we undertake using large ground-based telescopes such as NASA's IRTF on Mauna Kea, Hawaii.

布里斯托天体物理学和行星物理学小组的工作方案需要使用世界上最大的望远镜进行仔细的观测。该提案要求为前往这些望远镜提供两年的资金，以便对无法远程运行的项目进行观测。在研究微波背景辐射（大爆炸遗留下来的辐射）时，重要的是要消除前景辐射源的污染，这些污染会混淆我们对背景本身的测量。要消除这种污染，需要使用大型射电望远镜对我们目标场的无线电环境进行灵敏的观测。我们正在寻找的许多效应都与星系团中的气体在背景辐射上投射的“阴影”有关。我们也需要用光学和红外线望远镜来研究星系团，测量星系团的质量，从而了解星系团在宇宙历史中是如何形成和变化的。有些污染性射电源就在星系团中，而这些“活动星系”的核心中有超大质量黑洞，这也是我们研究的另一个主题。我们主要使用轨道X射线望远镜研究这些物体的物理学，但在无线电，红外线和光学波段成像也是必不可少的。在这里，我们再次使用大型地面望远镜，特别是美国的JVLA，澳大利亚的ATCA和智利的ESO大型望远镜。这项工作的一个主要目的是了解活跃星系如何将能量注入宇宙中的气体，帮助保持星系之间的气体温度，从而成为X射线的强大来源。这些活跃星系的小尺度模型可以在我们自己的银河系中找到，在黑洞系统中，质量是太阳质量的几倍。对这些系统的研究与对活动星系中重得多的黑洞的研究使用了类似的技术，但需要经常重复地观察，以跟踪它们在亮度和结构上的快速变化。从这些信息中，我们可以发现物质在黑洞附近的行为。我们工作的一个统一线索是调查宇宙中的结构如何随着时间的推移而形成和变化。我们观测的很大一部分致力于寻找和表征最早的星系和星系团，然后看看年轻的物体与靠近我们银河系的老物体有何不同。同样，我们使用了各种各样的望远镜来进行这项工作，从智利的光学望远镜到澳大利亚和美国的射电望远镜，观察恒星和它们之间的气体。我们不仅可以比遥远的星系更详细地研究附近的星系，而且还可以观察较小的物体，这些物体太暗了，如果它们离得更远，就看不见了。对我们来说，研究最低质量的星系特别有趣，这是最常见的，但其性质却知之甚少，与较大的物体有很大的不同。这些小星系被认为是更大星系的组成部分。我们也研究我们自己的星系，观察恒星之间被超新星或年轻恒星加热的气体，以及发射相干（脉泽）辐射的致密气体块-这是非常明亮的，并随时间变化。气体运动告诉我们银河系是如何从恒星中分离出气体的，并可以用来测量银河系的距离。最后，我们还试图研究太阳系中行星和大型卫星的大气层。大气的形成和演化可以通过详细的光谱学来跟踪，我们使用大型地面望远镜，如美国宇航局在夏威夷莫纳克亚山的IRTF。