Probing the early growth of supermassive black holes with the environment of high-redshift quasars

用高红移类星体环境探索超大质量黑洞的早期生长

• 批准号: 19J11013
• 负责人: 何 晩秋
• 金额: $ 1.09万
• 依托单位: National Astronomical Observatory of Japan
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for JSPS Fellows
• 财政年份: 2019
• 资助国家: 日本
• 起止时间: 2019-04-25 至 2021-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-19J11013/
• 关键词: AGN; high-z universe

This work aims at probing the early growth of supermassive black holes in the early universe. Supermassive black holes, which can be over millions of solar masses, are found to be ubiquitous at the center of local massive galaxies, like our Milky Way. How are these monsters formed and evolved? Theoretical works suggest two possible origins: a heavy black hole seed or a typical stellar-mass black hole seed with powerful growth.In this work, thanks to the wide and deep imaging of the Hyper Suprime-Cam Subaru Strategic Program, we constructed a large sample of quasars (i.e., rapidly growing supermassive black holes) over a wide luminosity range at redshift 4 (around 1.5 Gyr after the BigBang). Compared to previous works, this work extends the magnitude coverage of quasar sample towards the deep end by over 2 order of magnitude. The wide magnitude range makes our quasar sample more numerous, and it can provide less-biased view on early growth of supermassive black holes.We estimated their black hole mass and Eddington ratio (which can be used to quantify accretion rate) using Keck/DEIMOS and AAT/AAOmega spectrograph. In this fiscal year, we utilized the information to trace back their possible growth tracks. Results suggest 1) those quasars need a heavy black hole seed to be formed even under the extreme growing mode; and 2) those quasars are tending to "shut-down" their vigorous growth to episodic growth afterwards.

这项工作旨在探索早期宇宙中超大质量黑洞的早期生长。超大质量黑洞，可以超过数百万个太阳质量，被发现在本地大质量星系的中心无处不在，比如我们的银河系。这些怪物是如何形成和进化的？理论工作提出了两种可能的起源：一个重黑洞种子或一个典型的恒星质量黑洞种子与强大的增长。在这项工作中，由于超超级凸轮斯巴鲁战略计划的广泛和深入的成像，我们构建了一个大样本的类星体（即，快速增长的超大质量黑洞）在红移4（大爆炸后约1.5 Gyr）的广泛光度范围内。与以往的工作相比，本工作将类星体样本的星等覆盖范围向深部扩展了2个数量级以上。我们利用Keck/DEIMOS和AAT/AAOmega摄谱仪估算了超大质量黑洞的质量和爱丁顿比（可用于量化吸积率）。在本财政年度，我们利用这些信息追溯其可能的增长轨迹。结果表明：1）即使在极端的生长模式下，这些类星体也需要一个重黑洞种子才能形成; 2）这些类星体倾向于“关闭”它们的蓬勃生长，然后才能幕式生长。

项目成果

Black hole mass and Eddington ratio distributions of the z=4 less-luminous quasars over the HSC Wide field

HSC 宽视场上 z=4 亮度较低的类星体的黑洞质量和爱丁顿比分布

• 发表时间: 2021
• 作者: 大橋完太郎;トーマス・ブルック;Griseldis Kirsch;久山雄甫;奥堀亜紀子;尾田知子;筒井瑞貴;中村紀彦;林玲穂;Wanqiu He
• 通讯作者: Wanqiu He