Hertfordshire Astronomy 2015-18

天体物理研究中心开展了从x射线到射电波长范围的观测项目，并通过计算机建模和模拟来支持这一研究。我们的研究范围从对长波高红移星系的观测，到对观测结果进行新颖的统计分析，以寻找太阳系外的行星。在这两个极端之间，我们进行了迄今为止最大的多波长调查，以了解银河系和麦哲伦系统的特性。我们的研究利用了所有主要的欧洲和国际天文观测站的观测结果，包括光学、无线电和亚毫米波长的地面观测站，以及从远红外到x射线波长的太空观测站。计算机模拟使我们更好地理解了在观测中检测到的物理过程，我们需要应用先进的数据挖掘技术来处理我们正在生成的~ tb数据集。下面是我们在这些领域的研究的简要描述。我们通过搜索附近的恒星来发现行星。我们特别针对低质量的M型恒星，因为它们是宇宙中主要的恒星类型，尚未被搜索到。我们专注于通过多普勒摆动进行探测，并寻找周期性地使其母星黯然失色的行星。在拨款期间，我们期望在附近恒星的可居住区域首次探测到地球质量的行星。我们还发现，跟踪和模拟温度与行星温度重叠的最冷的褐矮星的特性。这些研究的目的是澄清棕矮星的数量，并确定它们的形成模式如何与不同质量的同类相适应。重的（恒星）或轻的（行星）。银河系是我们的家星系。其中以气体和尘埃形式存在的物质是形成恒星和行星系统的原材料。在恒星生命结束时，这些物质中的一些仍然被锁在恒星残骸中，但其中大部分在后期的超风阶段和超新星爆炸中返回。通过注入气体的热能和机械能，青年时期的吸积和老年时期的流出之间的循环丰富了气体介质，并控制了它的动力学。通过使用大面积成像调查，我们的研究着眼于银河系及其主要卫星麦哲伦星云内的气体、尘埃和恒星是如何联系在一起的。我们的调查跨越光学到亚毫米域，跟踪恒星，消光，分子云，它们的尘埃特性和相关的恒星形成。放眼银河系之外，我们有可能评估恒星是如何在不同的环境中形成和演化的，从小型矮星系到像我们这样的其他星系的外部。我们研究星系的气体含量，为恒星形成提供材料，并将我们的发现与恒星种群和本地星系的恒星形成区域联系起来。通过了解附近宇宙中触发恒星形成和恒星演化的过程，我们可以将这种理解应用于最早的星系和遥远宇宙中第一代恒星。事实上，我们的一些工作侧重于在亚毫米波长下高效探测到的高红移星系，并期待利用ALMA进行此类研究。新一代的调查正在绘制出最遥远的星系，并使我们能够研究恒星形成过程和超大质量黑洞的增长之间的联系。我们还使用详细的x射线和无线电观测来测量超大质量黑洞喷射到遥远星系和星系团的能量，影响恒星形成和气体特性，并在它们的进化史中发挥长期作用。

The Centre for Astrophysics Research carries out observational programmes spanning the wavelength range from X-ray to radio - supporting this by computer modelling and simulation. Our research ranges from observations of high-redshift galaxies at long wavelengths through to novel statistical analyses of observations seeking to detect planets outside our Solar System. In between these extremes, we carry out the largest multi-wavelength surveys conducted to date to understand the properties of the Milky Way and Magellanic System. Our research makes use of observations from all of the main European and international astronomical observatories, including ground-based observatories at optical, radio and submillimetre wavelengths, and space observatories at wavelengths ranging from the far infrared to X-rays. Computer simulations gives us a better understanding of the physical processes detected in our observations, and we need to apply advanced data-mining techniques to work with the ~terabyte datasets we are generating. Below is a brief description of our research in each of these areas.We perform searches of nearby stars to discover planets. We especially target low mass M stars since they are the dominant type of star in the Universe and have not yet been searched. We focus on detection through Doppler wobble and by looking for planets periodically eclipsing their parent star. During the period of the grant we expect to make the first detections of Earth-mass planets in the habitable zones of nearby stars. We also discover, follow-up and model the properties of the coolest brown dwarfs whose temperatures overlap with those of planets. These studies aim to clarify the population of brown dwarfs and to establish how their modes of formation fit in with those of their brethren of different masses, ie. heavier (stars) or lighter (planets). The Milky Way is our home galaxy. Material within it, in the form of gas and dust is the raw material for forming stars and planetary systems. At the end of stellar lives some of this material remains locked up in stellar remnants but much of it is returned in late superwind phases and supernova explosions. The cycle between accretion in youth and outflow in old age enriches the gaseous medium and rules its dynamics, via the thermal and mechanical energy injected into the gas. By using large area imaging surveys, our research looks at how gas, dust and stars within the Milky Way and its major satellite, the Magellanic Clouds, are linked up. Our surveys span the optical to sub-mm domains tracing stars, extinction, molecular clouds, their dust properties and associated star formation.Looking beyond the Milky Way, it is possible to appraise how stars form and evolve in different environments, from small dwarf galaxies to the outer parts of other galaxies like our own. We study the gas content of galaxies, providing the material for star formation, and link what we find to stellar populations and to star forming regions in the full range of local galaxies. By understanding the processes that trigger star formation and stellar evolution in the nearby Universe, we can apply this understanding to the very earliest galaxies and the first generations of stars in the distant Universe. Indeed some of our work focuses on high redshift galaxies detected with great efficiency at sub-millimetre wavelengths, and look forward to exploiting ALMA for such studies.A new generation of surveys is mapping out the most distant galaxies, and allows us to investigate what links the processes of star formation and the growth of supermassive black holes. We also use detailed X-ray and radio observations to measure the energy injected by jets ejected from supermassive black holes into distant galaxies and clusters of galaxies, affecting star formation and gas properties, and playing a long-term role in their evolutionary history.