Connecting Astrophysics and Fundamental Physics

连接天体物理学和基础物理学

• 批准号: RGPIN-2017-03756
• 负责人: Heyl, Jeremy
• 金额: $ 3.35万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=710518
• 关键词: Connecting; Astrophysics; Fundamental; Physics

The astrophysics of stars and compact objects (neutron stars, white dwarfs and black holes) constrain fundamental physics in crucial and unique ways. Furthermore, over the past several years astronomers and physicists have opened two new windows onto the Universe: gravitational radiation and neutrinos. In the near future astronomers will be able to probe the Universe with x-ray polarimetry. I propose several lines of research that exploit these unique and timely opportunities. In particular I propose a series of studies to probe the properties of weakly interacting particles in stars in globular clusters: both theoretical and observational investigations. Second I propose to develop techniques to constrain the neutron star equation of state using a combination of x-ray polarimetry, timing and spectroscopy including the effects of QED birefringence that produces unique signatures on the polarization of x-ray radiation from neutron stars. The third direction is gravitational. In particular I will explore how electromagnetic observations can best probe the properties of accreting black holes. Our recent studies of the stellar populations in the core of 47 Tucanae demonstrate how a holistic approach to modelling the data can reap great rewards. Specifically we model the evolution of the stars in the cluster including stellar evolution, dynamics and atmospheres starting from the fundamental physical equations all the way to a prediction of the observed data including the observational biases. To obtain constraints on the underlying physics we have to constrain the astrophysical uncertainties, so we simulate the entire evolution of a star from the main sequence to the oldest white dwarfs and use observations and models of the entire process. We now have similar data for over 50 other globular clusters so we can further mitigate the astrophysical uncertainties by studying the stars in a variety of environments. Observations of x-ray polarization from neutron stars and black holes will providing estimates of their structure and the magnetic fields that surround these objects. I propose to develop theoretical models of the emission regions of x-ray pulsars (that haven't be updated since the eighties) and the magnetic fields surrounding black holes. The goal is to bring the theoretical models all the way to the observational realm to predict the observed distribution of photon energies, polarization directions and arrival times to understand these objects in the greatest detail.

恒星和致密天体（中子星、白色矮星和黑洞）的天体物理学以关键而独特的方式制约着基础物理学。此外，在过去的几年里，天文学家和物理学家已经打开了两个新的宇宙窗口：引力辐射和中微子。在不久的将来，天文学家将能够用X射线偏振测量法探测宇宙。我提出了几条利用这些独特而及时的机会的研究路线。特别是，我提出了一系列的研究，以探讨在球状星团中的恒星弱相互作用粒子的性质：理论和观测调查。第二，我建议开发的技术来约束中子星星状态方程的X射线偏振，定时和光谱学的组合，包括QED双折射的影响，产生独特的签名上的X射线辐射的偏振从中子星。第三个方向是重力。特别是，我将探讨如何电磁观测可以最好地探测吸积黑洞的属性。 我们最近对47 Tuccenda核心恒星群的研究表明，对数据进行建模的整体方法可以获得巨大的回报。具体来说，我们模拟了星团中恒星的演化，包括恒星演化、动力学和大气层，从基本物理方程一直到观测数据的预测，包括观测偏差。为了获得对基础物理的约束，我们必须约束天体物理的不确定性，所以我们模拟了一颗星星从主序星到最古老的白色矮星的整个演化过程，并使用整个过程的观测和模型。我们现在有超过50个其他球状星团的类似数据，因此我们可以通过研究各种环境中的恒星来进一步减轻天体物理学的不确定性。 对中子星和黑洞的x射线偏振的观测将提供对它们的结构和围绕这些物体的磁场的估计。我建议发展X射线双星发射区的理论模型（自80年代以来一直没有更新）和黑洞周围的磁场。目标是将理论模型一直带到观测领域，以预测观测到的光子能量分布，偏振方向和到达时间，以最详细地了解这些物体。