Astrophysics at Oxford: 2010-2015

牛津天体物理学：2010-2015

• 批准号: ST/H002456/1
• 负责人: Roger Davies
• 金额: $ 316.81万
• 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: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FH002456%2F1
• 关键词: Astrophysics; Oxford; 2010; 2015

Astrophysicists at Oxford are trying to determine six basic things about the Universe. (1) What is it made of? The Universe appears to be at the beginning of a period of accelerated expansion driven by some mysterious stuff known as 'dark energy'. Einstein had a theory for what this stuff is: he called it the Cosmological Constant. We will be testing his theory by measuring the apparent brightnesses of distant exploding stars (supernovae), by measuring the distortions of distant galaxies as light is bent by the gravity of more nearby galaxies, and by measuring the precise positions of about one million galaxies. (2) What is the history of Hydrogen in the Universe? Hydrogen - the most abundant element in the Universe - is the most important building material for making stars. Atoms of Hydrogen combine into molecules within dense clouds, and these clouds provide the nursery for the birth of new stars. We will be using giant new telescopes operating at millimetre and radio wavelengths to observe, and hence understand, this process throughout most of the history of the Universe. (3) What can we learn about how galaxies formed from galaxies observed at current times? We are involved in large observational programmes that can be viewed as 'archaeology' of nearby galaxies looking for clues of important events in their history, for example by finding fast-moving gas orbiting a dormant supermassive black hole. We also study the relation between stellar populations and dark matter by studying the orbits of stars within and beyond the optical light in a galaxy. (4) What can we learn about how galaxies formed from distant galaxies observed at earlier times? Because of the finite speed of light, distant galaxies are seen when the Universe, and the galaxies within it, were young, and often these galaxies are so dusty that they are only effectively studied using infrared and radio observations. We map out the large-scale distribution of galaxies in the distant Universe using a combination of wide-field imaging (taking pictures) and spectroscopy (spreading light out into its constituent colours). We study these systems as they form and evolve, sometimes in dramatic bursts of star formation associated with supermassive black holes. (5) When did the first galaxies form? The Hydrogen in the Universe formed atoms about 300,000 years after the Big Bang, but was largely re-ionized (converted back to protons and electrons) during the so-called Epoch of Reionization. We use giant ground-based telescopes and satellites (e.g. the Hubble Space Telescope) to study these first galaxies and determine whether it was radiation associated with the birth of these galaxies, or stars within them, that was responsible for the re-ionization. (6) How do black holes influence star and galaxy formation? Black holes grow by 'gobbling up' gas and stars in a process called accretion. This process seems commonly to yield outflows in the form of winds and jets, the latter capable of reaching speeds very close to the speed of light. We study these systems in our own galaxy and in distant galaxies to determine the physics of such 'feedback mechanisms' (growth of the black hole is halted, albeit temporarily, by outflows driven by processes associated with the black hole). Our aim is to understand the influence of (compact) black holes on the formation of stars, galaxies and clusters of galaxies on much large physical scales.

牛津大学的天体物理学家正试图确定宇宙的六个基本特征。(1)它是用什么做的？宇宙似乎正处于加速膨胀时期的开始，这一时期是由一些被称为“暗能量”的神秘物质驱动的。爱因斯坦有一个关于这种物质的理论：他称之为宇宙常数。我们将通过测量遥远的爆炸恒星（超新星）的视亮度，通过测量遥远星系的扭曲，因为光被附近星系的引力弯曲，以及通过测量大约一百万个星系的精确位置来测试他的理论。(2)氢在宇宙中的历史是什么？氢-宇宙中最丰富的元素-是制造恒星的最重要的建筑材料。氢原子联合收割机在稠密的云层中结合成分子，这些云层为新恒星的诞生提供了温床。我们将使用巨大的新望远镜在毫米和无线电波长下工作，以观察并了解整个宇宙历史的这一过程。(3)我们能从当前观测到的星系中了解到星系是如何形成的吗？我们参与了大型观测计划，可以被视为附近星系的“考古学”，寻找其历史上重要事件的线索，例如通过寻找围绕休眠超大质量黑洞运行的快速移动气体。我们还通过研究星系中可见光以内和以外的恒星轨道来研究恒星数量与暗物质之间的关系。(4)关于星系是如何从早期观测到的遥远星系形成的，我们能学到什么？由于光速有限，当宇宙和其中的星系年轻时，可以看到遥远的星系，并且这些星系通常是如此尘土飞扬，以至于只能使用红外线和无线电观测来有效地研究它们。我们使用宽视场成像（拍照）和光谱学（将光传播到其组成颜色）的组合来绘制遥远宇宙中星系的大规模分布。我们研究这些系统的形成和演化，有时是在与超大质量黑洞相关的星星形成的戏剧性爆发中。(5)第一个星系是什么时候形成的？宇宙中的氢在大爆炸后大约30万年形成了原子，但在所谓的再电离时期，大部分被重新电离（转化回质子和电子）。我们使用巨大的地面望远镜和卫星（例如哈勃太空望远镜）来研究这些第一个星系，并确定是否是与这些星系的诞生有关的辐射，或者其中的恒星，负责再电离。(6)黑洞如何影响星星和星系的形成？黑洞通过“吞噬”气体和恒星而成长，这一过程被称为吸积。这个过程似乎通常会产生以风和喷流形式的外流，后者能够达到非常接近光速的速度。我们在我们自己的星系和遥远的星系中研究这些系统，以确定这种“反馈机制”的物理学（黑洞的生长被与黑洞相关的过程驱动的流出所停止，尽管是暂时的）。我们的目标是了解（紧凑）黑洞对恒星，星系和星系团在更大的物理尺度上形成的影响。

项目成果

The ATLAS3D project - XVIII. CARMA CO imaging survey of early-type galaxies

ATLAS3D 项目 - XVIII。

• DOI: 10.1093/mnras/sts299
• 发表时间: 2013
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Alatalo K

THE FIRST CATALOG OF ACTIVE GALACTIC NUCLEI DETECTED BY THE FERMI LARGE AREA TELESCOPE

• DOI: 10.1088/0004-637x/715/1/429
• 发表时间: 2010-01
• 期刊: The Astrophysical Journal
• 作者: A. Abdo;A. Abdo;M. Ackermann;M. Ajello;A. Allafort;E. Antolini;E. Antolini;W. Atwood;M. Axelss

Design concepts for the Cherenkov Telescope Array CTA: an advanced facility for ground-based high-energy gamma-ray astronomy

• DOI: 10.1007/s10686-011-9247-0
• 发表时间: 2011-12-01
• 期刊: EXPERIMENTAL ASTRONOMY
• 影响因子: 3
• 作者: Actis, M.;Agnetta, G.;Zychowski, P.
• 通讯作者: Zychowski, P.

Introducing the CTA concept

• DOI: 10.1016/j.astropartphys.2013.01.007
• 发表时间: 2013-03-01
• 期刊: ASTROPARTICLE PHYSICS
• 影响因子: 3.5
• 作者: Acharya, B. S.;Actis, M.;Zychowski, P.
• 通讯作者: Zychowski, P.

The Subaru-XMM-Newton Deep Survey (SXDS). VIII. Multi-wavelength identification, optical/NIR spectroscopic properties, and photometric redshifts of X-ray sources

斯巴鲁-XMM-牛顿深度勘测 (SXDS)。

• DOI: 10.1093/pasj/psv050
• 发表时间: 2015
• 期刊: Publications of the Astronomical Society of Japan
• 影响因子: 2.3
• 作者: Akiyama M