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。此奖助金申请是为了延长滚动奖助金的支持。在接下来的五年里，我们将继续进行一项以吸积黑洞和星系团为中心的研究计划。宇宙中最明亮的非爆炸源是活跃的星系和类星体，它们由一个吸积黑洞提供能量。这些天体发射的大部分x射线都来自黑洞附近，那里的引力非常强。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，在最内层半径处的物质的发射光谱以一种由我们首先发现的、很容易识别的方式被高度扭曲。我们建议使用x射线光谱及其变异性来测量这些相对论性畸变。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。通过最内层轨道的位置，我们将测量黑洞的旋转。中心大质量黑洞产生的能量会对其宿主星系产生深远的影响。当星系处于星系群或星系团的中心，能量通过喷流发射出来时，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在周围气体中膨胀和上升。同心波纹表明能量从我们发现的巨大声波中的气泡中流出，并消散加热周围的气体。以这种方式传递的能量阻止了大部分气体的快速冷却和形成大量的新恒星。冷气体的细丝被气泡拖来拖去，从而标记出星团核心的速度场。为了理解这个重要的星系反馈过程，包括加热/冷却平衡是如何以及何时建立的，冷却和恒星形成的程度是多少，以及它在多大程度上适用于所有大质量星系的形成，我们将分析和解释对群和星团核心的x射线和更长的波长观察。为研究天体物理学中这些令人兴奋的基础课题的博士后研究助理提供资助，为期五年。

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.