The Final Step: Establishing the Relations Between Black-Hole Growth and Host-Galaxy Properties During the Last Half of Cosmic Time

过去二十年中最重要的发现之一是认识到星系的生命及其中心超大质量黑洞（SMBH）是不可分割地交织在一起的，事实上，它们在宇宙时间中共同进化。从真实的意义上说，要更清楚地了解一个的形成和演变，就必须了解另一个。在高红移（z = 0.5 - 3）的观测研究揭示了引人注目的星系SMBH的共同进化，尽管相对较小的样本量，几乎可以肯定地限制了影响SMBH增长的因素的充分考虑。该研究小组将利用来自深场和宽场多波长星系调查的丰富现有数据，对低到中等红移（z = 0 - 0.8）的星系-SMBH共同演化进行彻底调查，这一时期覆盖了宇宙时间的最后一半，将非常遥远的宇宙中的SMBH星系特性与我们在当地观察到的特性联系起来。该提案还将支持研究生研究以及初中/高中教师发展研讨会。研究团队将利用现有的宽视场多波长（X射线到远红外）调查来识别大约7，100个具有活动星系核的星系（AGN，即，活跃吸积的SMBH），包括近200个矮星系，来自z = 0 - 0.8的300，000个星系，这包括比可比研究大得多的样本。紫外-远红外数据将产生星系红移，恒星质量（M*），星星形成率（SFR），和结构参数，而X射线光度将被用来估计时间平均SMBH吸积率（BHAR），这最大限度地减少了活动星系核的内在变化的影响。收集的数据将用于进行统计学上稳健的部分相关性和多参数研究，以解决多条调查线，例如（例如）将IlustrisTNG模拟套件与观测到的BHAR相结合，以预测z = 0 SMBH质量与宿主星系M* 的关系，并评估合并和吸积对SMBH增长的相对重要性。其他需要考虑的问题包括：在宇宙时间的后半部分，SMBH和星系凸起是否继续同步增长？矮星系的黑洞“生长”方式是否与更大质量的星系不同？活动星系核的存在是否以某种方式使星系保持在恒星形成星系的“主序星”上？该奖项反映了NSF的法定使命，并被认为是值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估的支持。

One of the most important discoveries of the last two decades has been the realization that the lives of galaxies and their central super-massive black holes (SMBH) are inextricably intertwined, and in fact, have evolved together over cosmic time. In a real sense, a clearer understanding of the formation and evolution of one depends on that of the other. Observational studies at high redshift (z = 0.5 - 3) reveal compelling galaxy-SMBH coevolution despite relatively small sample sizes that almost certainly limit a full accounting of the factors influencing SMBH growth. The research team will take advantage of the wealth of existing data from deep and wide-field multi-wavelength galaxy surveys to conduct a thorough investigation of galaxy-SMBH coevolution over low-to-moderate redshifts (z = 0 - 0.8), an epoch covering roughly the final half of cosmic time, to connect SMBH-galaxy properties in the very distant universe with those we observe locally. The proposal will also support graduate research as well as middle/high-school teacher development workshops.The research team will exploit existing wide-field multi-wavelength (X-ray to far-infrared) surveys to identify approximately 7,100 galaxies with active galactic nuclei (AGN, i.e., actively accreting SMBHs), including nearly 200 dwarf galaxies, from a total of 300,000 galaxies spanning z = 0 – 0.8, which comprises a much larger sample than comparable studies. The UV-to-far-infrared data will yield galaxy redshifts, stellar masses (M*), star formation rates (SFRs), and structural parameters, while X-ray luminosities will be used to estimate the time-averaged SMBH accretion rate (BHAR), which minimizes the influence of intrinsic AGN variability. The collected data will be used to conduct statistically robust partial-correlation and multi-parameter studies to address multiple lines of inquiry, such as (e.g.) combining the IlustrisTNG simulation suite with the observed BHAR to predict the z = 0 SMBH mass vs. host galaxy M* relation and assess the relative importance of mergers and accretion on SMBH growth. Other questions to be considered include: do SMBHs and galaxy bulges continue to grow in lockstep over the last half of cosmic time? Do dwarf galaxies “grow” their black holes differently than more massive galaxies, and does the presence of an AGN somehow keep galaxies on the star-forming galaxy “main sequence”?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.