A rolling grant for the observation and study of cosmic X-ray sources (Apr 2009 to Mar 2014)

天文研究所的X射线小组分析和解释了来自大多数宇宙X射线望远镜和仪器的数据。本次助学金申请是为其续签滚动助学金的支持。在接下来的五年里，我们将继续执行一项以吸积黑洞和星系团为中心的研究方案。宇宙中最明亮的非爆炸性来源是活动星系和类星体，它们由一个吸积的黑洞提供动力。这些天体发出的大部分X射线都来自引力非常强的黑洞附近。这导致了高速度和大红移，包括多普勒和引力，以及强烈的光弯曲。因此，最内半径物质的发射光谱以一种由我们最先发现的、很容易识别的方式严重扭曲。我们建议使用X射线光谱及其变异性来测量这些相对论失真。这些结果可以用来确定吸积流的几何形状和X射线连续体的来源。通过最内侧轨道的位置，我们将测量黑洞的自转。中心大质量黑洞产生的能量可以对其宿主星系产生深远的影响。当星系处于一组或一组星系的中心，能量通过喷流发射时，这一点可以被生动地观察到。X射线图像显示，充满相对论等离子体的气泡正在膨胀，并通过周围的气体上升。同心波纹显示了能量在我们发现的巨大声波中从气泡中流出，并消散了对周围气体的加热。通过这种方式传递的能量阻止了大部分气体迅速冷却并形成大量新恒星。冷气体的细丝被气泡拖来拖去，从而标记出星系团核心的速度场。我们将分析和解释对星团和星系团核心的X射线和更长波长的观测，以了解这一重要的星系反馈过程，包括如何以及何时建立加热/冷却平衡，发生多少冷却和恒星形成，以及它在多大程度上适用于所有大质量星系的形成。为一个五年计划寻求资助博士后研究助理从事这些激动人心的天体物理学基本主题的工作。

The X-ray Group at the Institute of Astronomy has analysed and interpreted data from most cosmic X-ray telescopes and instruments. This grant application is to renew the rolling grant for its support. Over the next five years we shall pursue a programme of research centred on accreting black holes and clusters of galaxies. The most luminous non-explosive sources in the Universe are active galaxies and quasars, which are powered by an accreting black hole. Most of the X-ray emission from these objects originates close to the black hole where gravity is very strong. This causes high velocities and large redshifts, both doppler and gravitational, as well as strong bending of light. The emission spectrum from matter at the innermost radii is consequently highly distorted in a manner first discovered by us and which is easily recognised. We propose to measure these relativistic distortion using both the X-ray spectrum and its variability. The results can then be used to determine the geometry of the accretion flow and the source of the X-ray continuum. Through the location of the innermost orbit, we shall measure the spin of the black hole. The energy produced by a central massive black hole can have a profound effect on its host galaxy. This can be vividly observed when the galaxy is at the centre of a group or cluster of galaxies and the energy is emitted through jets. X-ray images show bubbles filled with relativitic plasma inflating and rising through the surrounding gas. Concentric ripples show energy flowing away from the bubbles in giant sound waves discovered by us and which dissipate heating the surrounding gas. The energy transferred in this way stops much of the gas from cooling rapidly and forming massive amounts of new stars. Filaments of cold gas are dragged around by the bubbles so marking the velocity field of the cluster core. We shall analyse and interpret X-ray and longer wavelength observations of the cores of groups and clusters in order to understand this important galaxy feedback process, including how and when a heating/cooling balance is established, how much cooling and star formation takes place and how much it applies to the formation of all massive galaxies. Funding for Postdoctoral Research Assistants to work on these exciting and fundamental topics in astrophysics is sought for a five year programme.