Galaxy-scale jets with new extragalactic radio surveys

银河级喷射机与新的河外无线电勘测

• 批准号: 1947458
• 金额: --
• 依托单位: The Open University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1947458
• 关键词: Galaxy; scale; jets; new; extragalactic

Extragalactic jets from supermassive black holes are known to play an important role in the process of how galaxies evolve. Research in this area over the last decade has focused particularly on powerful jets in the centres of rich galaxy clusters, where jets appear to regulate star formation in massive galaxies - a process now incorporated into most cosmological simulations of galaxy formation. But smaller jets contained within their host galaxies can also have a powerful effect on the scale of individual galaxies, as we have found from recent X-ray studies measuring the impact of their shocks (e.g. Croston et al. 2007, 2009, Mingo et al. 2011, 2012, Heesen et al. 2014). Their low radio luminosity and small size mean that these jets have been difficult to identify in previous radio surveys. For this reason, the demographics of the population, and the role of these small-scale jets in the high-redshift Universe, are not understood. Similarly, direct measurements of their impact via X-ray follow up have only been possible for a handful of objects.This project will involve exploiting new low-frequency surveys of the extragalactic sky with LOFAR (the Low-Frequency Array), which have the sensitivity, resolution and image fidelity to identify and characterize galaxy-scale jets. By cross-matching this population with data at other wavelengths, it will be possible to answer questions about how common they are, and how their radio properties relate to their black hole mass, accretion behaviour and environment. There is also the possibility to work on new and archival X-ray observations to measure shock properties in individual objects.

众所周知，来自超大质量黑洞的河外喷流在星系演化过程中发挥着重要作用。过去十年，这一领域的研究特别关注丰富星系团中心的强大喷流，其中喷流似乎调节大质量星系中的恒星形成——这一过程现已纳入大多数星系形成的宇宙学模拟中。但是，宿主星系中包含的较小喷流也可以对单个星系的规模产生强大的影响，正如我们从最近测量其冲击影响的 X 射线研究中发现的那样（例如 Croston 等人，2007 年、2009 年、Mingo 等人） 2011，2012，Heesen 等人，2014）。它们的射电亮度低且尺寸小，这意味着这些喷流在之前的射电勘测中很难识别。因此，人口统计数据以及这些小型喷流在高红移宇宙中的作用尚不清楚。同样，通过 X 射线跟踪直接测量其影响也只能对少数天体进行。该项目将涉及利用 LOFAR（低频阵列）对河外天空进行新的低频勘测，LOFAR 具有灵敏度、分辨率和图像保真度来识别和表征星系尺度喷流。通过将这些群体与其他波长的数据进行交叉匹配，将有可能回答有关它们有多常见以及它们的无线电特性与黑洞质量、吸积行为和环境有何关系的问题。还有可能进行新的和存档的 X 射线观测，以测量单个物体的冲击特性。