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: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=689237
• 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、白矮星和黑洞）的天体物理学以关键且独特的方式限制着基础物理学。此外，在过去的几年里，天文学家和物理学家打开了两个观察宇宙的新窗口：引力辐射和中微子。在不久的将来，天文学家将能够利用 X 射线偏振测量法来探测宇宙。我提出了利用这些独特而及时的机会进行几项研究。我特别提出了一系列研究来探讨球状星团中恒星中弱相互作用粒子的特性：理论和观测研究。其次，我建议开发结合 X 射线偏振测量、计时和光谱学的技术来约束中子星状态方程，其中包括 QED 双折射效应，该效应对中子星 X 射线辐射的偏振产生独特的特征。第三个方向是引力。我将特别探讨电磁观测如何最好地探测吸积黑洞的特性。******我们最近对 47 个杜鹃座核心恒星群的研究表明，数据建模的整体方法如何能够获得巨大的回报。具体来说，我们对星团中恒星的演化进行建模，包括恒星演化、动力学和大气，从基本物理方程开始，一直到对观测数据（包括观测偏差）的预测。为了获得对基础物理的约束，我们必须限制天体物理的不确定性，因此我们模拟了恒星从主序星到最古老的白矮星的整个演化过程，并使用整个过程的观测和模型。我们现在拥有 50 多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的不确定性。******中子星和黑洞的 X 射线偏振观测将提供对其结构和围绕这些物体的磁场的估计。我建议开发 X 射线脉冲星发射区域（自 80 年代以来一直没有更新）和黑洞周围磁场的理论模型。目标是将理论模型一直带入观测领域，以预测观测到的光子能量分布、偏振方向和到达时间，从而最详细地了解这些物体。