Supermassive black holes and nuclear stellar disks, nuclear keys to galaxy formation and evolution

超大质量黑洞和核星盘，星系形成和演化的核关键

• 批准号: ST/F009186/1
• 负责人: Marc Sarzi
• 金额: $ 41.68万
• 依托单位: University of Hertfordshire
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FF009186%2F1
• 关键词: Supermassive; black; holes; nuclear; stellar

Like the pieces of a Cosmic Jigsaw, galaxies come in different shapes and colours. Understanding how galaxies evolved their present-day properties is one of the most important and longstanding issues in astronomy. Among the scientists in this field, common wisdom has it that galaxies formed from a combination of star-formation episodes, during which gas turns into young blue stars, and merging events, whereby galaxies collide and reassemble into different galactic configurations. If galaxies formed all at once, they would only become redder as their stellar population ages, without changing their shape. Whereas the star-formation history of galaxies has been measured by many observations, the pace at which galaxies merge through cosmic times remains largely unknown. In this respect, astronomers are left only with the predictions of their models. According to the widely accepted model of a Universe dominated by cold dark matter, because galaxies grow in mass over time by merging together, the largest galaxies have assembled just recently, whereas the smallest galaxies were already in place early on in the history of the Universe. Furthermore, galaxies in groups or clusters should have assembled before their counterparts in less densely populated environments. Galaxies can indeed find it difficult to merge once they crowd together. This is because they tend to swing by each other too fast for them to coalesce. As an Advanced Fellow I will test these theoretical predictions. For this investigation I will adopt as a record of the time when galaxies merged together the age of the stars in the small disks that are often found in the centre of galaxies. Numerical simulations show that such nuclear disks are easily destroyed when galaxies collides, so that their presence in a given galaxy indicates that no such a catastrophic event occurred since the disk formed. If the cold dark matter model is correct, I should find that nuclear disks are made of older stars in smaller galaxies, or in those living in the most crowded galactic environments. By the turn of the century, another puzzling component of galaxies turned out to have a key role in galaxy formation and evolution: Supermassive Black Holes. Once considered by astronomers only as a theoretical possibility, supermassive black holes have now been found to lurk at the center of many galaxies, including our Milky Way. Most importantly, the mass of the central black holes appears to scale with the mass of their host galaxies, or only to that of the bulge component of disk galaxies. Roughly speaking, central black holes have been found to be almost one thousand times less massive than their host galaxy or bulge. This striking coincidence between objects that are vastly different in size, with supermassive black holes extending at most to the size of our Solar system, strongly suggests that the evolution of supermassive black holes and galaxies is intimately related. The universality of this relationship, however, is not yet established. This is because the mass of supermassive black holes has been measured only in a limited number of galaxies, and almost exclusively in certain kinds. It would be surprising if galaxies that formed in different ways were found to share the same black-hole mass content. As an Advanced Fellow, I will complete the demography of supermassive black holes using large ground-based telescopes that can correct for the atmospheric blurring with the aid of bright reference stars or point sources created in the upper atmosphere by powerful lasers. This will allow me to measure the mass of supermassive black holes as if I were using the Hubble space telescope, and to observe precisely those galaxies for which there are very few black-hole mass measurements. Using these new data I will test the universality of the relationship between supermassive black holes and galaxies, and shed more light on the nature of this link.

就像宇宙拼图的碎片一样，星系有不同的形状和颜色。了解星系是如何演化成今天的性质是天文学中最重要和最长期的问题之一。在这一领域的科学家中，普遍的看法是星系是由恒星形成事件和合并事件的组合形成的，在恒星形成事件中，气体变成年轻的蓝色恒星，而合并事件则是星系碰撞并重新组合成不同的星系配置。如果星系同时形成，它们只会随着恒星数量的增加而变得更红，而不会改变它们的形状。虽然星系的恒星形成历史已经被许多观测所测量，但星系在宇宙时代合并的速度仍然是未知的。在这方面，天文学家只剩下他们的模型的预测。根据被广泛接受的宇宙由冷暗物质主导的模型，因为星系通过合并在一起随着时间的推移而增加质量，最大的星系最近才聚集起来，而最小的星系在宇宙历史的早期就已经存在了。此外，星系群或星系团中的星系应该在人口密度较低的环境中先于它们的同类聚集。一旦它们聚集在一起，星系团确实很难合并。这是因为他们往往摆动对方太快，他们合并。作为一名高级研究员，我将测试这些理论预测。在这项研究中，我将采用星系合并在一起的时间记录，即在星系中心经常发现的小圆盘中恒星的年龄。数值模拟表明，当星系碰撞时，这种核盘很容易被破坏，因此它们在给定星系中的存在表明自盘形成以来没有发生过这样的灾难性事件。如果冷暗物质模型是正确的，我应该会发现核盘是由较小星系中的较老恒星组成的，或者是那些生活在最拥挤的星系环境中的恒星。到了世纪之交，星系中另一个令人困惑的组成部分被证明在星系的形成和演化中起着关键作用：超大质量黑洞。曾经被天文学家认为只是理论上的可能性，现在已经发现超大质量黑洞潜伏在许多星系的中心，包括我们的银河系。最重要的是，中心黑洞的质量似乎与其宿主星系的质量成比例，或者仅与盘星系的凸起部分的质量成比例。粗略地说，已经发现中心黑洞的质量比它们的宿主星系或凸起小近1000倍。这一惊人的巧合发生在大小相差悬殊的天体之间，超大质量黑洞最多延伸到我们太阳系的大小，这强烈表明超大质量黑洞和星系的演化是密切相关的。然而，这种关系的普遍性尚未确立。这是因为超大质量黑洞的质量只在有限数量的星系中被测量过，而且几乎只在某些类型中。如果发现以不同方式形成的星系具有相同的黑洞质量含量，那将是令人惊讶的。作为一名高级研究员，我将使用大型地面望远镜完成超大质量黑洞的人口统计，这些望远镜可以在明亮的参考星或由强大激光在高层大气中产生的点源的帮助下校正大气模糊。这将使我能够测量超大质量黑洞的质量，就像我使用哈勃太空望远镜一样，并精确地观察那些黑洞质量测量很少的星系。利用这些新数据，我将测试超大质量黑洞和星系之间关系的普遍性，并进一步阐明这种联系的本质。

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 ATLAS3D project - XVI. Physical parameters and spectral line energy distributions of the molecular gas in gas-rich early-type galaxies

ATLAS3D 项目 - XVI。

• DOI: 10.1093/mnras/sts598
• 发表时间: 2013
• 期刊: Monthly Notices of the Royal Astronomical Society
• 影响因子: 4.8
• 作者: Bayet E

NGC 1266 AS A LOCAL CANDIDATE FOR RAPID CESSATION OF STAR FORMATION

NGC 1266 是恒星形成迅速停止的本地候选者

• DOI: 10.1088/0004-637x/780/2/186
• 发表时间: 2013
• 期刊: The Astrophysical Journal
• 作者: Alatalo K

DISCOVERY OF AN ACTIVE GALACTIC NUCLEUS DRIVEN MOLECULAR OUTFLOW IN THE LOCAL EARLY-TYPE GALAXY NGC 1266

• DOI: 10.1088/0004-637x/735/2/88
• 发表时间: 2011-04
• 期刊: The Astrophysical Journal
• 作者: K. Alatalo;L. Blitz;L. Young;T. Davis;M. Bureau;Laura A. Lopez;M. Cappellari;N. Scott;K. Shapiro;A. Crocker;Sergio Martín;M. Bois;F. Bournaud;R. Davies;P. Zeeuw;P. Duc;E. Emsellem;Jesus Falcon-Barosso;S. Khochfar;D. Krajnović;H. Kuntschner;P. Lablanche;R. McDermid;R. Morganti;T. Naab;T. Oosterloo;M. Sarzi;P. Serra;A. Weijmans

The Atlas3D Project - VI. Simulations of binary galaxy mergers and the link with Fast Rotators, Slow Rotators, and Kinematically Distinct Cores

Atlas3D 项目 - VI。

• DOI: 10.48550/arxiv.1105.4076
• 发表时间: 2011
• 作者: Bois M