Astrophysics at Southampton

南安普敦天体物理学

• 批准号: ST/M001326/1
• 负责人: Ian McHardy
• 金额: $ 121.48万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2015
• 资助国家: 英国
• 起止时间: 2015 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FM001326%2F1
• 关键词: Astrophysics; Southampton

Understanding accretion onto, and emission from, compact objects, including the relationship between high energy (X and Gamma-ray) emission and optical and radio emission, with particular emphasis on time domain studies, remains an important part of group research. Previously our main strengths were in the study of solar-mass scale compact objects, eg X-ray binary sources (XRBs). Whilst we retain this strength, the recent expansion of the group, coupled with considerable turnover of staff, has enabled us to enhance our research in the extragalactic and cosmological areas where previously we were less strong. Thus, overall, the group is more balanced.On the most local scales, we are expanding our studies of the earth's magnetosphere to encompass that of other planets within our own solar system, particularly Saturn, to improve our understanding of magnetospheric field line reconnection. Magnetic fields are important in jet formation so we will be investigating the magnetic field line strengths in jets in star-forming regions and young stellar objects to improve our understanding of protostellar evolution. On small 'compact object' scales we are modelling the evolution of the strange Super Fast X-ray Transients (SFXTs), originally discovered by the ESA Gamma-ray/hard X-ray observatory, INTEGRAL, whose development we led. We also wish to understand the physics behind magnetic accretion onto rotating neutron stars in XRBs and model the 3D accretion structures. We also wish to understand the transition from accretion powered neutron stars in XRBs to rotation powered radio pulsars at lower accretion rates. We will study, by observation and modelling, whether the behaviour of accretion physics at near the maximum possible (Eddington) accretion rate is the same for systems of all black hole (BH) masses.We are carrying out a deep eMERLIN radio legacy survey (LeMMINGs) of a complete sample of 280 nearby galaxies to determine whether the local environment (ie galaxy type) or BH mass affects the accretion onto the supermassive BH in the nucleus. We will also discover the exact relationship between BH mass, radio and X-ray luminosities in different galaxy types. For X-ray bright AGN we are quantifying the geometry of their central X-ray sources and surrounding material, eg accretion discs, in the strong gravitational fields around black holes by General Relativistic modelling of the time lags between X-ray energy bands. We are also trying to understand the relationship between the X-ray emission in AGN and that in the optical and radio bands.Much of the observed behaviour of compact objects on all scales may be explained by surrounding outflows which modify and reprocess the nuclear emission, producing optical/uv emission lines and resulting in variable X-ray absorption. We are developing a wind model to explain these observations for AGN. Jets from AGN, through feedback of energy, can seriously affect the growth and appearance of surrounding galaxies and clusters. We are carrying out the first survey to determine how this interaction actually occurs at high redshift (z > 1). To provide a cosmological framework into which our other work can fit, we are modelling the large scale evolution of galaxies and their distribution via semi-analytic techniques, including energy input from AGN. These models will be compared with the evolving luminosity functions of AGN and SFGs we will derive from the deepest eMERLIN survey (eMERGE). On the very largest scales we are measuring the geometry of the universe itself using Supernovae as standard candles.Although our work is mostly based on observations, almost all cases now contain a substantial fraction of theoretical or computer modelling. This modelling is obvious in the galaxy evolution and QSO wind cases but is also very important, eg, in SFXTs and neutron star XRBs and in AGN X-ray lags.

了解致密物体的吸积和发射，包括高能（X和伽马射线）发射与光学和无线电发射之间的关系，特别强调时域研究，仍然是小组研究的一个重要部分。以前，我们的主要优势是在太阳质量尺度的紧凑对象，如X射线双星源（XRB）的研究。虽然我们保留了这一实力，但最近该小组的扩大，加上工作人员的大量更替，使我们能够加强我们在河外和宇宙学领域的研究，而这些领域以前我们不太强大。因此，总体而言，小组是更平衡的。在最局部的尺度上，我们正在扩大我们的研究地球的磁层，包括我们自己的太阳系内的其他行星，特别是土星，以提高我们的理解磁层磁力线重联。磁场在喷流形成中很重要，因此我们将研究恒星形成区域和年轻恒星物体中喷流的磁力线强度，以提高我们对原恒星演化的理解。在小的“紧凑物体”尺度上，我们正在模拟奇怪的超快X射线瞬变（SFXT）的演变，该瞬变最初由ESA伽马射线/硬X射线天文台INTEGRAL发现，我们领导了该天文台的开发。我们还希望了解XRB中旋转中子星的磁吸积背后的物理学，并模拟3D吸积结构。我们也希望了解从吸积动力的中子星在XRB的旋转动力的无线电天体在较低的吸积率的过渡。我们将通过观察和建模，吸积物理学在接近最大可能时的行为（爱丁顿）吸积率是相同的系统的所有黑洞（BH）的质量。我们正在进行一项深入的eMERLIN无线电遗产调查（LeMMINGs）的280个附近星系的完整样本，以确定当地环境是否（即星系类型）或黑洞质量影响到核中超大质量黑洞的吸积。我们还将发现不同星系类型中BH质量、射电和X射线光度之间的确切关系。对于X射线明亮的活动星系核，我们正在通过X射线能带之间的时间滞后的广义相对论模型来量化它们的中心X射线源和周围物质的几何形状，例如黑洞周围强引力场中的吸积盘。我们还试图了解活动星系核中的X射线发射与光学和射电波段的X射线发射之间的关系，在所有尺度上观察到的致密天体的许多行为都可以用周围的外流来解释，这些外流修改和再处理了核发射，产生了光学/紫外发射线，并导致了可变的X射线吸收。我们正在发展一个风模型来解释活动星系核的这些观测结果。来自活动星系核的喷流，通过能量反馈，可以严重影响周围星系和星系团的生长和外观。我们正在进行第一次调查，以确定这种相互作用实际上是如何发生在高红移（z > 1）。为了提供一个宇宙学框架，我们的其他工作可以适应，我们正在模拟大规模的星系演化及其分布通过半解析技术，包括从活动星系核的能量输入。这些模型将与我们将从最深的eMERLIN调查（eMERGE）得出的AGN和SFG的光度函数进行比较。在最大的尺度上，我们用超新星作为标准烛光来测量宇宙本身的几何形状。虽然我们的工作主要是基于观测，但现在几乎所有的情况都包含了相当大一部分的理论或计算机建模。这种模型在星系演化和类星体风的情况下是明显的，但也是非常重要的，例如，在SFXTs和中子星星XRB和活动星系核X射线滞后。

项目成果

A White Paper on keV sterile neutrino Dark Matter

• DOI: 10.1088/1475-7516/2017/01/025
• 发表时间: 2016-02
• 期刊: Journal of Cosmology and Astroparticle Physics
• 影响因子: 6.4
• 作者: R. Adhikari;M. Agostini;N. A. Kỳ;T. Araki;M. Archidiacono;M. Bahr;J. Baur;J. Behrens;Fedor Bez

High-resolution VLA observations of FR0 radio galaxies: properties and nature of compact radio sources

FR0 射电星系的高分辨率 VLA 观测：紧凑射电源的特性和性质

• DOI: 10.48550/arxiv.1810.01894
• 发表时间: 2018
• 作者: Baldi R

BLACK HOLE AND GALAXY COEVOLUTION FROM CONTINUITY EQUATION AND ABUNDANCE MATCHING

• DOI: 10.1088/0004-637x/810/1/74
• 发表时间: 2015-09-01
• 期刊: ASTROPHYSICAL JOURNAL
• 影响因子: 4.9
• 作者: Aversa, R.;Lapi, A.;Danese, L.
• 通讯作者: Danese, L.

LeMMINGs - I. The eMERLIN legacy survey of nearby galaxies. 1.5-GHz parsec-scale radio structures and cores

• DOI: 10.1093/mnras/sty342
• 发表时间: 2018-02
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: R. D. Baldi;D. Williams;I. McHardy;R. Beswick;M. Argo;M. Argo;B. T. Dullo;J. Knapen;J. Knapen;E. Brinks;T. Muxlow;S. Aalto;A. Alberdi;G. Bendo;S. Corbel;S. Corbel;R. Evans;D. Fenech;D. Green;H. Klöckner;E. Körding;P. Kharb;T. Maccarone;I. Martí-Vidal;C. Mundell;F. Panessa;A. Peck;M. Pérez-Torres;D. Saikia;P. Saikia;P. Saikia;F. Shankar;R. Spencer;I. Stevens;P. Uttley;J. Westcott

High-resolution VLA observations of FR0 radio galaxies: the properties and nature of compact radio sources

FR0 射电星系的高分辨率 VLA 观测：紧凑射电源的特性和性质

• DOI: 10.1093/mnras/sty2703
• 发表时间: 2018
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Baldi R