PATT Linked Grant Support for the Bristol Astrophysics Group

布里斯托天体物理学小组正在进行一些需要用世界上最大的望远镜进行仔细观测的方案。该提案要求提供两年的资金，用于前往这些望远镜的旅费和工作期间的生活费。在研究大爆炸遗留下来的微波背景辐射时，重要的是要从前景发射源中去除污染物，这些污染物会混淆我们对背景本身的测量。这是通过美国和其他地方的射电望远镜进行的一系列观测来完成的。许多测量与星系团在微波背景上投射的“阴影”有关。对这些星团进行广泛的无线电和光学研究，以了解它们的质量并深入了解它们是如何形成的，也是我们工作的重要组成部分。我们对活动星系的研究主要是使用轨道X射线望远镜进行的，这些星系的核中有非常大的黑洞，但是为了理解发射的物理学，还必须看到无线电，红外线和光学波段的发射。在这方面，小组成员再次广泛使用世界各地的望远镜，从澳大利亚的射电干涉仪到智利的光学望远镜。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，在质量是太阳质量几倍的黑洞系统中。对这些系统的研究与对活动星系的研究是一样的，但需要跟踪黑洞附近物质发射亮度的快速变化，这告诉我们物质的下落和相关的高速流喷射的物理学。我们河外工作的一个统一线索是宇宙中的结构如何随着时间的推移而形成和变化。因此，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团，然后看看最遥远的星系和星团与那些离我们更近的星系和星团有何不同，这些星系和星团因此在宇宙生命的后期被看到，因此更古老。在这项工作中必须使用从无线电到光学的各种地面望远镜，其中大部分工作使用智利欧洲南方天文台的望远镜。附近的星系可以比更遥远的星系更详细地研究，我们也会研究附近星系的种群-特别是那些质量最低的星系，它们在数量上占主导地位，并且具有与它们更大质量的表亲截然不同的性质。最后，我们还研究了我们自己的银河系，观察恒星之间的气体，这些气体已经被超新星或年轻恒星加热，并在密集的气体块中发射相干（微波激射）辐射。

The Bristol Astrophysics Group works on a number of programmes that require careful observations to be made with the world's largest telescopes. This proposal requests two years of funding for travel to those telescopes and subsistence while working at them. In studies on 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. This is done using a series of observations at radio-telescopes in the USA and elsewhere. Many of the measurements relate to the 'shadows' cast on the microwave background by clusters of galaxies. Extensive radio and optical studies of those clusters, to understand their masses and to gain insights into how they formed, are also a significant part of our work. Our work on active galaxies, which host very massive black holes in their nuclei, is principally done using orbiting X-ray telescopes, but to understand the physics of the emission it is essential to see also the emission in the radio, infra-red, and optical bands. Here again Group members make extensive use of telescopes world-wide, from the radio interferometers in Australia to optical telescopes in Chile. 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 is done in the same way as for the active galaxies, with the extra requirement to follow rapid changes in the brightness of emission from matter near the black holes that tell us about the physics of the infall of matter and the associated ejection of high-speed flows. A unifying thread of our extragalactic work is on how structure in the Universe forms and changes over time. A large fraction of our observing is therefore dedicated to finding and characterizing the earliest galaxies and clusters, and then seeing how the most distant galaxies and clusters differ from those closer to us, which are therefore seen later in the life of the Universe, and so are older. A wide range of ground-based telescopes has to be used in this work, from the radio to the optical, with much of the work using the telescopes of the European Southern Observatory in Chile. Nearby galaxies can be studied in more detail than the more distant ones, and we also look at the populations of galaxies nearby - especially those of the lowest mass, which dominate the galaxy population by number, and have properties that can be quite different from their more massive cousins. Finally, we also work on 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.