Raising the bar for black hole mass measurements in lower mass galaxies

提高低质量星系中黑洞质量测量的标准

• 批准号: 2009122
• 负责人: Monica Valluri
• 金额: $ 41.05万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2009122&HistoricalAwards=false
• 关键词: Raising; bar; black; hole; mass

It is now known that supermassive black holes live at the centers of all galaxies. Over the past decade scientists have found that the masses of these monster black holes depend strongly on the properties of their host galaxies. Supermassive black holes, some of the most intriguing objects in the universe, also play a transformative role in how their parent galaxies evolve. While they are gigantic (between a million and a ten billion times the mass of the sun), supermassive black holes are only a fraction of a percent of the total mass of the galaxy they live in. Much is still not understood about how these black holes grew or how they were able to so dramatically influence galaxy evolution. To understand how black holes grow, it is first necessary to measure their masses, both in nearby galaxies and in distant galaxies. The ‘gold standard’ method for measuring black hole masses in nearby galaxies uses the motions of stars that orbit close to the black hole. In the nearby Universe most of the black holes that are still growing today (the so-called Active Galactic Nuclei) live in disk galaxies like our own Milky Way. The black holes in disk galaxies are less massive, and therefore are harder to study since they have weaker effects on the motion of stars around them. The team will develop training tools to allow other scientists to use their new modeling software. Several undergraduate research students will participate in this research adding to their scientific and technical training and better equipping them for future pursuits.The accurate determination of supermassive black hole masses in galaxies, both at low and high redshifts, underpins almost all efforts to understand galaxy evolution. Black hole mass measurements that use the dynamics of stars in galactic nuclei are the current ‘gold standard’. Black hole masses are found to be tightly correlated with the properties of their host galaxies over a very wide range of black hole masses (from 100 million to 10 billion times the mass of the sun). At lower black holes masses, found in predominantly disk-like galaxies, the correlations are weaker. Spiral galaxies like our Milky Way, that contain a stellar bar (a rapidly rotating cigar-like central feature) show the most scatter. The team recently found that black hole mass measurements in barred galaxies can be overestimated when the bar is ignored, especially as the galaxy is viewed more face-on. Since 65% of disk galaxies have stellar bars, this bias primarily affects black hole masses in galaxies at the low-end of the mass function. It also impacts the black hole mass scaling relations - the correlations between the host galaxy properties and black hole masses. The new black hole mass measurements resulting from this project will better constrain the statistical uncertainties on the black hole masses at the low end of the black hole mass range, where it is most uncertain. They will also aid in determining the “reverberation mapping” mass scale a relationship that is crucial for future measurements of black hole masses at high redshift. The modeling will yield detailed three-dimensional distributions of the orbits of stars in the host galactic nuclei. The open source software that will be developed during this project will have broad applicability beyond black hole mass determination. The team will also make available tutorials for using the software for modeling galaxies and involve several undergraduates in the research allowing them to apply state-of- the-art galactic dynamics modeling tools to real data.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

现在我们知道，超大质量黑洞存在于所有星系的中心。在过去的十年里，科学家们发现这些巨型黑洞的质量很大程度上取决于其宿主星系的性质。超大质量黑洞是宇宙中最有趣的物体之一，也在其母星系的演化中发挥着变革性的作用。虽然它们是巨大的（在太阳质量的100万到100亿倍之间），但超大质量黑洞只是它们所在星系总质量的一小部分。关于这些黑洞是如何成长的，或者它们如何能够如此戏剧性地影响星系的演化，还有很多事情还不清楚。要了解黑洞是如何成长的，首先需要测量它们的质量，无论是在附近的星系还是在遥远的星系。测量附近星系中黑洞质量的“黄金标准”方法是利用靠近黑洞轨道的恒星的运动。在附近的宇宙中，大多数今天仍在增长的黑洞（所谓的活动星系核）生活在像我们银河系这样的盘状星系中。盘状星系中的黑洞质量较小，因此更难研究，因为它们对周围恒星运动的影响较弱。 该团队将开发培训工具，让其他科学家使用他们的新建模软件。几名本科研究生将参与这项研究，增加他们的科学和技术培训，并为他们未来的追求提供更好的装备。星系中超大质量黑洞质量的准确测定，无论是在低红移还是高红移，都是理解星系演化的几乎所有努力的基础。利用星系核中恒星的动力学来测量黑洞质量是目前的“黄金标准”。黑洞的质量与其宿主星系的性质密切相关，在很宽的黑洞质量范围内（从太阳质量的1亿到100亿倍）。在较低的黑洞质量，主要是盘状星系中发现的，相关性较弱。 像我们的银河系这样的螺旋星系，包含一个恒星棒（一个快速旋转的雪茄状中心特征），显示出最分散的特征。该团队最近发现，当忽略棒时，棒星系中的黑洞质量测量可能会被高估，特别是当星系被更多地正面观察时。由于65%的盘星系具有恒星棒，这种偏差主要影响质量函数低端的星系中的黑洞质量。它还影响了黑洞质量的标度关系-宿主星系性质和黑洞质量之间的相关性。 该项目产生的新的黑洞质量测量将更好地限制黑洞质量范围低端的黑洞质量的统计不确定性，在那里它是最不确定的。它们还将有助于确定“混响映射”质量尺度，这种关系对于未来测量高红移黑洞质量至关重要。该模型将产生详细的三维分布的恒星轨道的主机星系核。在这个项目期间开发的开源软件将具有广泛的适用性，超出黑洞质量测定的范围。 该团队还将提供使用该软件进行星系建模的教程，并让几名本科生参与研究，使他们能够将最先进的星系动力学建模工具应用于真实的数据。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Robotic Reverberation Mapping of the Southern Seyfert NGC 3783

• DOI: 10.3847/1538-4357/abccd4
• 发表时间: 2021-01-01
• 期刊: ASTROPHYSICAL JOURNAL
• 影响因子: 4.9
• 作者: Bentz, Misty C.;Street, Rachel;Valluri, Monica
• 通讯作者: Valluri, Monica

Reverberation Mapping of IC 4329A

• DOI: 10.3847/1538-4357/acab62
• 发表时间: 2022-12
• 期刊: The Astrophysical Journal
• 作者: M. Bentz;C. Onken;R. Street;M. Valluri

The Mass of the Black Hole in NGC 5273 from Stellar Dynamical Modeling

• DOI: 10.3847/1538-4357/acc4bc
• 发表时间: 2022-12
• 期刊: The Astrophysical Journal
• 作者: Katie A. Merrell;E. Vasiliev;M. Bentz;M. Valluri;C. Onken

The Black Hole Mass of NGC 4151 from Stellar Dynamical Modeling

• DOI: 10.3847/1538-4357/ac05b6
• 发表时间: 2021-06
• 期刊: The Astrophysical Journal
• 作者: C. Roberts;M. Bentz;E. Vasiliev;M. Valluri;C. Onken

Orbital Support and Evolution of Flat Profiles of Bars (Shoulders)

• DOI: 10.3847/1538-4357/ace976
• 发表时间: 2023-03
• 期刊: The Astrophysical Journal
• 作者: Leandro Beraldo e Silva;V. Debattista;S. Anderson;M. Valluri;P. Erwin;Kathryne J. Daniel;N. Deg