Astrophysics at Oxford 2016-2019

牛津天体物理学 2016-2019

• 批准号: ST/N000919/1
• 负责人: Steven Balbus
• 金额: $ 426.83万
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FN000919%2F1
• 关键词: Astrophysics; Oxford; 2016; 2019

Astrophysical research at Oxford University is carried out by investigators with widespread interests, spanning scales from planetary to cosmic. Our activities are universal, in every sense of this word. We are actively engaged with many of the most exciting questions of modern physics. On the familiar scale of planetary phenomena, we seek to understand how the oceans, atmospheres and climate patterns of distant worlds behave. We are investigating how other solar systems form and evolve, and why they seem to be so different from our own.Stars are the historical staple of our discipline. We are investigating the processes by which binary stars merge, and how discs and great jets form from accreting, X-ray emitting gas when one of the stars is a black hole. On larger scales associated with the Milky Way Galaxy, we study the combined motions of individual stars in great detail, using the results to understand how the Galaxy maintains its structure, and how a great halo of invisible dark matter reveals its presence indirectly through the motions of visible luminous matter. Gas in galaxies accretes onto central black holes, with consequences that range from spectacular in the case of quasars and active galactic nuclei, to barely a blip in the case of our own Galaxy. Oxford researchers study the Galactic Centre to understand its detailed physics, and probe gas molecules in distant galaxies to reveal the properties of the black holes harboured in their own central regions. While the gas that forms stars is initially very cool, much of the gas in galaxies is very hot and dilute. These completely ionised space plasmas, which couple strongly to magnetic fields, exhibit very unusual and complex behaviour, many aspects of which are not at all understood. Oxford researchers seek to understand how particles are accelerated to enormous energies in plasma shock waves, and in calculating whether protons and electrons interact and mutually heat one another when they are part of an accretion flow. These are problems that are critical to our understanding of fundamental processes of kinetic theory, whose significance extends well beyond the boundary of astrophysics. The formation and evolution of galaxies is influenced by their environment, which is in turn greatly impacted by the presence of the galaxies themselves. To unravel the details of this throughout cosmic time is an enormous task, requiring the acquisition and analysis of vast amounts of observational data. Oxford Astrophysics maintains a large, active group of researchers pursuing this grand problem in all of its scope, from the highest redshifts at which galaxies form, down through present cosmic times. Questions pertaining to the rate of star formation, to how galaxy morphology itself may change with time, to whether the presence of neighbours causes spin alignment, to how the central black hole develops, are all being investigated at Oxford. This involves the use of current facilities as well as planning the design and implementation of key instruments to be associated with major international collaborations. The largest scales of all are associated with the CMB, the cosmic microwave background. The exquisitely difficult but essential process of excising the foreground contamination from our own Galaxy (both polarised and unpolarised) is led by the Oxford team developing the C-BASS instrument. Oxford researchers are developing techniques to coax profound secrets of the universe from very sensitive data. What were the initial tiny fluctuations that gave rise to galaxies and their larger scale clusters? What constraints can be placed on the masses of elementary particles or on deviations from classical general relativity? By combining information from CMB instruments like Planck with other data sets related to galaxy clustering, powerful new tools are being developed.

牛津大学的天体物理学研究是由兴趣广泛的研究人员进行的，研究范围从行星到宇宙。我们的活动在任何意义上都是普遍的。我们积极地研究现代物理学中许多最令人兴奋的问题。在熟悉的行星现象范围内，我们试图了解遥远世界的海洋、大气和气候模式是如何运作的。我们正在研究其他太阳系是如何形成和演化的，以及为什么它们看起来与我们的太阳系如此不同。明星是我们学科历史上的主要人物。我们正在研究双星合并的过程，以及当其中一颗恒星是黑洞时，盘状物和巨大的喷流是如何从吸积的x射线发射气体中形成的。在与银河系相关的更大尺度上，我们非常详细地研究了单个恒星的联合运动，利用这些结果来理解银河系是如何保持其结构的，以及一个由不可见暗物质组成的巨大光环是如何通过可见发光物质的运动间接揭示它的存在的。星系中的气体会聚集到中心的黑洞上，其结果从类星体和活跃星系核的壮观景象到我们银河系的微弱景象不等。牛津大学的研究人员研究银河系中心，以了解其详细的物理特性，并探测遥远星系中的气体分子，以揭示黑洞在其中心区域的特性。虽然形成恒星的气体最初是很冷的，但星系中的大部分气体是非常热和稀释的。这些完全电离的空间等离子体与磁场强烈耦合，表现出非常不寻常和复杂的行为，其中许多方面根本不为人所知。牛津大学的研究人员试图了解粒子如何在等离子体冲击波中被加速到巨大的能量，并计算质子和电子在吸积流中是否相互作用和相互加热。这些问题对于我们理解运动论的基本过程至关重要，其意义远远超出了天体物理学的界限。星系的形成和演化受到其环境的影响，而环境又受到星系本身存在的极大影响。要在整个宇宙时间里揭开这一现象的细节是一项艰巨的任务，需要获取和分析大量的观测数据。牛津天体物理学院拥有一支庞大而活跃的研究团队，从星系形成时的最高红移，一直到现在的宇宙时代，在所有范围内都在研究这个大问题。有关恒星形成速度、星系形态本身如何随时间变化、邻居的存在是否会导致自旋排列、中心黑洞如何发展等问题，都在牛津大学进行研究。这包括利用现有设施以及规划设计和执行与主要国际合作有关的关键文书。其中最大的尺度与CMB有关，即宇宙微波背景。牛津大学开发C-BASS仪器的团队负责从我们自己的星系（包括极化和非极化）中去除前景污染的过程，这一过程非常困难，但却是必不可少的。牛津大学的研究人员正在开发一种技术，从非常敏感的数据中获取宇宙的深奥秘密。最初的微小波动是什么导致了星系和更大规模的星团的形成？对基本粒子的质量或对经典广义相对论的偏差有什么限制？通过将普朗克等CMB仪器的信息与其他与星系群集相关的数据集相结合，强大的新工具正在开发中。

项目成果

The total rest-frame UV luminosity function from 3 < z < 5: a simultaneous study of AGN and galaxies from -28 < M UV < -16

总静止帧 UV 光度函数为 3

• DOI: 10.1093/mnras/stad1333
• 发表时间: 2023
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Adams N

K2 photometry and HERMES spectroscopy of the blue supergiant ? Leo: rotational wind modulation and low-frequency waves

蓝超巨星的 K2 光度测定和 HERMES 光谱？

• 发表时间: 2018
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Aertsthanks C.

The rest-frame UV luminosity function at $z \simeq 4$: a significant contribution of AGN to the bright-end of the galaxy population

$z simeq 4$ 处的静止帧紫外光度函数：AGN 对星系群亮端的显着贡献

• 发表时间: 2019
• 期刊: arXiv e-prints
• 作者: Adams N. J.

Evolution of the galaxy stellar mass function: evidence for an increasing M * from z = 2 to the present day

星系恒星质量函数的演化：M * 从 z = 2 到现在不断增加的证据

• DOI: 10.1093/mnras/stab1956
• 发表时间: 2021
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Adams N

Evolution of the galaxy stellar mass function: evidence for an increasing $M^*$ from $z=2$ to the present day

星系恒星质量函数的演化：从 $z=2$ 到现在 $M^*$ 不断增加的证据

• DOI: 10.48550/arxiv.2101.07182
• 发表时间: 2021
• 作者: Adams N