Understanding the symbiosis between galaxy evolution and AGN activity

了解星系演化与活动星系核活动之间的共生关系

• 批准号: ST/G001758/1
• 负责人: Clive Tadhunter
• 金额: $ 36.73万
• 依托单位: University of Sheffield
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FG001758%2F1
• 关键词: Understanding; symbiosis; between; galaxy; evolution

Active galaxies have unusually bright star-like nuclei which cannot be explained in terms of the normal thermal emission of the hundreds of billions of stars that make up the galaxy haloes. It is though that such active galactic nuclei (AGN) result from the heating of gas accreted by super-massive black holes in the centres of the galaxies as part of the overall galaxy evolution process. In a major advance it has recently been shown that the masses of the super-massive black holes -- typically between a million and a billion times the mass of our Sun -- are closely related to the masses of the host galaxies. It has been suggested that this close relationship can be explained in terms of the negative feedback effect of the AGN: as the super-massive black holes grow through the accretion of gas they drive powerful outflows that eventually expel the gas from galaxies, halting the AGN activity and any further star formation in the galaxy haloes. The AGN feedback effect can also help to explain why there are relatively few high mass galaxies in the local Universe: the AGN outflows prevent galaxies from growing too massive by expelling the cooling gas that would otherwise form stars. However, despite its potentially key importance for understanding the evolution of galaxies, the AGN feedback effect is largely a theoretical construct, and does not yet have a solid basis in direct observations of active galaxies in the local Universe. There also remain large uncertainties about how and when the gas required to trigger the AGN activity is accreted as the galaxies evolve. Therefore we propose to use state-of-the-art techniques, based on the over 15 years research experience of the AGN group in Sheffield, to measure the powers of the AGN outflows in a variety of nearby active galaxies, and also investigate the dominant AGN triggering mechanism. This will allow us to assess the true significance of AGN for our general understanding of the galaxy evolution.

活跃星系具有异常明亮的恒星状核，这不能用组成星系晕的数千亿颗恒星的正常热辐射来解释。这种活动星系核（AGN）是由星系中心超大质量黑洞吸积的气体加热而产生的，这是整个星系演化过程的一部分。最近的一项重大进展表明，超大质量黑洞的质量（通常是太阳质量的100万到10亿倍）与宿主星系的质量密切相关。有人认为，这种密切的关系可以用活动星系核的负反馈效应来解释：当超大质量黑洞通过气体的吸积而成长时，它们会驱动强大的外流，最终将气体从星系中排出，停止活动星系核的活动，并停止星系晕中任何进一步的星星形成。活动星系核的反馈效应也可以帮助解释为什么局部宇宙中的高质量星系相对较少：活动星系核的外流通过排出冷却气体来防止星系变得太大，否则会形成恒星。然而，尽管AGN反馈效应对于理解星系的演化具有潜在的关键重要性，但它在很大程度上是一种理论构建，并且在直接观测局部宇宙中的活动星系时还没有坚实的基础。随着星系的演化，触发活动星系核活动所需的气体如何以及何时被吸积，这一点也存在很大的不确定性。因此，我们建议使用最先进的技术，在谢菲尔德AGN组超过15年的研究经验的基础上，测量各种附近活动星系的AGN外流的功率，并探讨活动星系核的主导触发机制。这将使我们能够评估活动星系核对于我们对星系演化的总体理解的真正意义。

项目成果

TORUS AND ACTIVE GALACTIC NUCLEUS PROPERTIES OF NEARBY SEYFERT GALAXIES: RESULTS FROM FITTING INFRARED SPECTRAL ENERGY DISTRIBUTIONS AND SPECTROSCOPY

• DOI: 10.1088/0004-637x/736/2/82
• 发表时间: 2011-05
• 期刊: The Astrophysical Journal
• 作者: A. Alonso-Herrero;C. Ramos Almeida;R. Mason;A. Asensio Ramos;P. Roche;N. Levenson;M. Elitzur;C. Packham;J. M. Rodríguez Espinosa;S. Young;T. Díaz-Santos;A. Pérez-García

The environments of luminous radio galaxies and type-2 quasars

发光射电星系和2型类星体的环境

• DOI: 10.48550/arxiv.1308.4725
• 发表时间: 2013
• 作者: Almeida C

THE ORIGIN OF THE INFRARED EMISSION IN RADIO GALAXIES. III. ANALYSIS OF 3CRR OBJECTS

射电星系中红外发射的起源。

• DOI: 10.1088/0004-637x/722/2/1333
• 发表时间: 2010
• 期刊: The Astrophysical Journal
• 作者: Dicken D

MOLECULAR CO(1-0) GAS IN THE z ~ 2 RADIO GALAXY MRC 0152-209

z ~ 2 无线电星系中的分子 CO(1-0) 气体 MRC 0152-209

• DOI: 10.1088/2041-8205/734/1/l25
• 发表时间: 2011
• 期刊: The Astrophysical Journal
• 作者: Emonts B

A LARGE-SCALE SHOCK SURROUNDING A POWERFUL RADIO GALAXY?

• DOI: 10.1088/2041-8205/734/2/l28
• 发表时间: 2010-11
• 期刊: The Astrophysical Journal Letters
• 作者: J. Croston;M. Hardcastle;B. Mingo;D. Evans;D. Evans;D. Dicken;R. Morganti;C. Tadhunter