Astrophysics at Keele: planets, stars and galaxies.

在理解我们在宇宙中的位置时，我们需要知道有多少行星，以及行星系统是如何形成和演化的。研究行星最好的方法就是找出从它们的恒星前面经过的行星。通过寻找由凌日行星引起的恒星光线的微小衰减，基尔的WASP-South调查发现了比南半球任何其他行星都多的凌日行星，并正在利用它们来回答有关行星系统如何形成的问题。行星围绕着年轻的恒星形成，恒星和行星的形成密切相关。基尔将处理对年轻恒星和星团进行的大规模调查的数据，使用欧洲南方天文台的甚大望远镜获得的光谱，与欧空局的盖亚任务即将获得的史无前例的天体测量相结合。这一组合将为恒星和星团的形成和演化提供迄今为止最大的调查。两个麦哲伦星云是距离我们的星系最近的两个星系，它们与我们的星系相互作用，提供了一个研究星系如何相互影响的绝佳机会，碰撞和合并被认为是解释当今星系的重要因素。Keele将利用Vista麦哲伦星云的近红外探测来绘制整个相互作用的星系的恒星形成图，并研究麦哲伦星云和我们的星系之间的恒星形成有何不同。在星系的核心，超大质量黑洞可以通过吸入周围物质来生长。现在人们意识到，围绕黑洞旋转产生的强风既可以调节黑洞的增长，也可以影响整个星系未来的演化。Keele领导的一个项目使用了最新的X射线卫星，研究了黑洞极端引力产生的X射线发射，以绘制出黑洞自转周期的分布，并研究它们如何与宿主星系相互作用。为了理解恒星和凌日恒星的行星，我们需要知道恒星质量和恒星半径之间的关系。这一点目前还不够准确，但我们可以通过使用新发现的食双星来测量质量和半径，从而绘制出质量-半径关系，从而改善这一点。

In understanding our place in the universe we need to know how many planets there are and how planetary systems form and evolve. The best way of studying planets is to find the ones that pass in front of ("transit") their star. By looking for the tiny dips in a star's light caused by a transiting planet, Keele's WASP-South survey has found more transiting planets than anyone else in the Southern hemisphere, and is using them to answer questions about how planetary systems form. Planets form around young stars, and star and planet formation are intimately connected. Keele will process the data from a very large survey of young stars and clusters of stars, using spectra obtained by ESO's Very Large Telescope, to combine with the unprecedented astrometry soon to be obtained by ESA's Gaia mission. The combination will provide the biggest survey yet of how stars and stellar clusters form and evolve.The two Magellanic Clouds are the two galaxies closest to our own, so close that they interact with our galaxy, providing an excellent opportunity to study how galaxies affect each other, with collisions and mergers thought to be important factors in explaining galaxies today. Keele will exploit the Vista Magellanic Cloud near-infrared survey to map out star formation across entire interacting galaxy systems and study how star formation differs between the Magellanic Clouds and our galaxy.At the cores of galaxies, supermassive black holes can grow by sucking in material from their surroundings. It is now realised that powerful winds generated by the swirling around a black hole can both regulate the growth of the black hole and affect the future evolution of the whole galaxy. A Keele-led program using the latest X-ray satellites studies the X-ray emission generated by the extreme gravity of the black hole to map out the distribution of the spin periods of the black holes, to study how they interact with their host galaxies. In order to understand both stars and planets transiting stars we need to know the relation between the masses and the radii of stars. This is not known accurately enough currently, but we can improve this by using newly discovered eclipsing binary stars to measure both masses and radii and thus map out the mass-radius relation.