Studies of Accretion onto Black Holes

黑洞吸积的研究

• 批准号: 1816420
• 负责人: Ramesh Narayan
• 金额: $ 33.06万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1816420&HistoricalAwards=false
• 关键词: Studies; Accretion; onto; Black; Holes

Some of the most luminous objects observed in the universe are associated with matter accreting onto black holes, either while they are forming, or as mature objects. This is important to study because black holes and their formation impact the evolution of galaxies and the production of atomic elements, as well as being a test case for general relativity and physics in extreme conditions. A research group at Harvard University will study multiple aspects of black hole accretion using computer simulation code developed by the group. The research will include investigations of (i) accretion onto a supermassive black hole when a star is torn apart by the black hole, (ii) the growth of supermassive black holes early in the universe, (iii) black hole accretion dominated by light subatomic particles called neutrinos in the collapse of a massive star, and (iv) similar accretion when two compact stars, called neutron stars, collide and merge. This work will form the bulk of the doctoral thesis of a student who is a member of a group that has been traditionally underrepresented in science. During the last decade and a half, general relativistic (GR) magnetohydrodynamic (MHD) codes have been developed and applied widely to black hole systems. The principal investigator of the project has developed the first GRMHD code to include radiation, a program called KORAL, and a radiation post-processor code, called HEROIC, which computes spectra of simulated models. Three research areas will be explored using simulations with KORAL and HEROIC: (i) Super-Eddington accretion onto a supermassive black hole in a tidal disruption event; (ii) the growth of supermassive black holes between redshift 20, when black hole seeds first formed in the universe, and redshift 6, when distant quasars are directly observed; (iii) Super-Eddington models of quasars and fits to observational data. KORAL will be modified to handle neutrino emission, absorption and transfer in neutrino-dominated accretion flows (NDAFs), which are present during core collapse of rapidly rotating massive stars. It will be applied to two problems: (i) NDAFs corresponding to the regimes of radiatively inefficient accretion, thin disk accretion, and super-neutrino-Eddington accretion, with applications to long gamma-ray bursts. (ii) Post-merger NDAFs in double neutron star mergers, with applications to short gamma-ray bursts.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.

宇宙中观察到的一些最亮的物体与黑洞上吸积的物质有关，无论是在黑洞形成时，还是作为成熟物体。 这对于研究很重要，因为黑洞及其形成影响星系的演化和原子元素的产生，并且是极端条件下广义相对论和物理学的测试用例。 哈佛大学的一个研究小组将使用该小组开发的计算机模拟代码研究黑洞吸积的多个方面。 该研究将包括以下方面的调查：(i) 当一颗恒星被黑洞撕裂时，超大质量黑洞的吸积；(ii) 宇宙早期超大质量黑洞的生长；(iii) 在大质量恒星坍塌中，由称为中微子的轻亚原子粒子主导的黑洞吸积；以及 (iv) 当两颗致密恒星（称为中子星）碰撞和合并时，类似的吸积。 这项工作将构成一名学生博士论文的大部分内容，该学生是一个传统上在科学领域代表性不足的群体的成员。 在过去的十五年里，广义相对论（GR）磁流体动力学（MHD）代码已经被开发出来并广泛应用于黑洞系统。该项目的首席研究员开发了第一个包含辐射的 GRMHD 代码，一个名为 KORAL 的程序，以及一个名为 HEROIC 的辐射后处理器代码，用于计算模拟模型的光谱。 将利用 KORAL 和 HEROIC 的模拟来探索三个研究领域：(i) 潮汐破坏事件中超大质量黑洞的超级爱丁顿吸积； (ii) 超大质量黑洞在红移 20 和红移 6 之间生长，红移 20 是黑洞种子首次在宇宙中形成，红移 6 是直接观测到遥远的类星体； (iii) 类星体的超级爱丁顿模型和观测数据的拟合。 KORAL 将进行修改，以处理中微子主导的吸积流 (NDAF) 中的中微子发射、吸收和转移，这种吸积流出现在快速旋转的大质量恒星的核心塌缩过程中。 它将应用于两个问题：（i）对应于辐射低效吸积、薄盘吸积和超中微子-爱丁顿吸积的体系的NDAF，并应用于长伽马射线暴。 (ii) 双中子星合并中的合并后 NDAF，以及短伽马射线暴的应用。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点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

First Sagittarius A* Event Horizon Telescope Results. IV. Variability, Morphology, and Black Hole Mass

• DOI: 10.3847/2041-8213/ac6736
• 发表时间: 2022-05
• 期刊: The Astrophysical Journal Letters
• 作者: Event Horizon Telescope Collaboration;K. Akiyama;A. Alberdi;W. Alef;J. Algaba;R. Anantua;K. Asada

Event Horizon Telescope imaging of the archetypal blazar 3C 279 at an extreme 20 microarcsecond resolution

事件视界望远镜以 20 微角秒的极限分辨率对原型耀变体 3C 279 进行成像

• DOI: 10.1051/0004-6361/202037493
• 发表时间: 2020
• 期刊: Astronomy & Astrophysics
• 影响因子: 6.5
• 作者: Kim Jae-Young;Krichbaum Thomas P.;Broderick Avery E.;Wielgus Maciek;Blackburn Lindy;Gomez Jose L.;Johnson Michael D.;Bouman Katherine L.;Chael Andrew;Akiyama Kazunori;Jorstad Svetlana;Marscher Alan P.;Issaoun Sara;Janssen Michael;Chan Chi-kwan;Savolainen
• 通讯作者: Savolainen

The Shadow of a Spherically Accreting Black Hole

• DOI: 10.3847/2041-8213/ab518c
• 发表时间: 2019-10
• 期刊: The Astrophysical Journal Letters
• 作者: R. Narayan;Michael D. Johnson;C. Gammie

Unraveling Twisty Linear Polarization Morphologies in Black Hole Images

• DOI: 10.3847/1538-4357/acc8cd
• 发表时间: 2022-10
• 期刊: The Astrophysical Journal
• 作者: R. Emami;Angelo Ricarte;G. Wong;D. Palumbo;Dominic O. Chang;S. Doeleman;A. Broderick;R. Narayan;M. Wielgus;L. Blackburn;B. Prather;A. Chael;R. Anantua;K. Chatterjee;I. Martí-Vidal;J. Gómez;K. Akiyama;M. Liska;L. Hernquist;G. Tremblay;M. Vogelsberger;C. Alcock;Randall A. Smith;J. Steiner;P. Tiede;F. Roelofs

Density jump as a function of magnetic field for collisionless shocks in pair plasmas: The perpendicular case

• DOI: 10.1063/1.5099000
• 发表时间: 2019-05
• 期刊: Physics of Plasmas
• 影响因子: 2.2
• 作者: A. Bret;Ramesh Narayan