WoU-MMA: Luminous Supermassive Black Hole Accretion Systems as High-Energy Neutrino Factories

WoU-MMA：作为高能中微子工厂的发光超大质量黑洞吸积系统

• 批准号: 2009884
• 负责人: Alexander Chekhovskoy
• 金额: $ 44.86万
• 依托单位: Northwestern University
• 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: 2020-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2009884&HistoricalAwards=false
• 关键词: WoU; MMA; Luminous; Supermassive; Black

For the past decade, NSF's Ice Cube observatory located in Antarctica has been on the hunt for energetic neutrinos. To make neutrinos, you need to smash small, subatomic particles together at near light speeds. While scientists have known this for a while, where nature hides its neutrino factories has remained a mystery. Recently, the decade-long pursuit led scientists to the galaxy TXS 0506+056. This galaxy emitted high-energy neutrinos alongside a pulse of light. Despite finding the galaxy, the scientists still do not understand what makes it into a neutrino factory. Using a computer code the researchers plan to develop, they will recreate the central regions of this galaxy inside of the world's largest supercomputers. They will then look inside of the cyber-galaxy for any places where particles accelerate and smash together. They will catalog all such places and identify those that emit both neutrinos and light, matching the observations of the real galaxy. This will help us to reveal the secrets of how and where nature makes energetic neutrinos and light, enabling the scientists around the world to better understand nature's neutrino factories. The PI will bring experiments into a local high-school and will involve high-school students in real-world data analysis and visualization. Students will gain experience working with Big Data, and they will set up in-class physical experiments. Neutrino production sites and their physical conditions are poorly understood. The fact that one high-energy neutrino was detected simultaneously with a gamma-ray flare suggested that both messengers originate in the same region, likely inside the relativistic jet. The discovery of roughly a dozen of high-energy neutrinos from the direction of TXS 0506+056 within ~6 months without any accompanying gamma-ray flare complicates the picture, as it implies that neutrinos and gamma-rays are not produced co-spatially.  Some questions to be answered include: What is the structure of radiative tilted thin disks around black holes? Where are the dissipation regions in such flows? What are the production sites of high-energy neutrinos? Are they produced via photo-hadronic or hadro-nuclear interactions? Why do most of the neutrinos coming from the direction of TXS 0506+056 have no bright electromagnetic counterpart? How do luminous accretion flows manage to produce powerful radio jets, defying the standard expectation that such disks are jet-phobic? What is the spectrum and variability of such flows? Understanding these issues will allow the scientific community to meaningfully and quantitatively interpret multi-messenger observations of black hole accretion. This award addresses/advances the goals of the Windows on the Universe Big Idea.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.

在过去的十年里，美国国家科学基金会位于南极洲的冰立方天文台一直在寻找高能中微子。为了制造中微子，你需要以接近光速的速度将小的亚原子粒子粉碎在一起。虽然科学家们已经知道这一点有一段时间了，但大自然把中微子工厂藏在哪里仍然是个谜。最近，经过长达十年的探索，科学家们发现了TXS 0506+056星系。这个星系释放出高能中微子和光脉冲。尽管发现了这个星系，科学家们仍然不明白是什么使它成为中微子工厂。利用研究人员计划开发的计算机代码，他们将在世界上最大的超级计算机中重建这个星系的中心区域。然后，他们将在网络星系内部寻找粒子加速和碰撞的任何地方。他们将对所有这样的地方进行分类，并识别出那些同时发射中微子和光的地方，与真实星系的观测结果相匹配。这将有助于我们揭示自然界如何以及在何处制造高能中微子和光的秘密，使世界各地的科学家能够更好地了解自然界的中微子工厂。PI将把实验带到当地的一所高中，并将让高中生参与现实世界的数据分析和可视化。学生将获得使用大数据的经验，他们将在课堂上建立物理实验。人们对中微子的产生地点及其物理条件了解甚少。一个高能中微子与一个伽马射线耀斑同时被探测到的事实表明，这两个信使来自同一个区域，很可能在相对论性喷流内部。在大约6个月内，从TXS 0506+056方向发现了大约12个高能中微子，没有任何伴随的伽马射线耀斑，这使情况变得复杂，因为这意味着中微子和伽马射线不是在空间上共同产生的。需要回答的一些问题包括：黑洞周围的辐射倾斜薄盘的结构是什么？这种流动的耗散区在哪里？高能中微子的产生点在哪里？它们是通过光强子或强子核相互作用产生的吗？为什么大多数来自TXS 0506+056方向的中微子没有明亮的电磁对应？明亮的吸积流如何能够产生强大的射电喷流，而不顾人们对这种圆盘有喷射恐惧的标准预期？这种流动的频谱和可变性是什么？了解这些问题将使科学界能够有意义和定量地解释黑洞吸积的多信使观测。该奖项旨在解决/推进宇宙之窗大构想的目标。该奖项反映了美国国家科学基金会的法定使命，并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，被认为值得支持。