Inferring astrophysical X-ray polarization with deep learning

Inferring telescope polarization properties through spectral lines without linear polarization

We present a technique to determine the polarization properties of a telescope through observations of spectral lines that have no intrinsic linear polarization signals. For such spectral lines, any observed linear polarization must be induced by the telescope optics. We apply the technique to observations taken with the SPINOR at the DST and demonstrate that we can retrieve the characteristic polarization properties of the DST at three wavelengths of 459, 526, and 615 nm. We determine the amount of crosstalk between the intensity Stokes I and the linear and circular polarization states Stokes…

Inferring kilonova population properties with a hierarchical Bayesian framework I : Non-detection methodology and single-event analyses

We present ${\tt nimbus}$ : a hierarchical Bayesian framework to infer the intrinsic luminosity parameters of kilonovae (KNe) associated with gravitational-wave (GW) events, based purely on non-detections. This framework makes use of GW 3-D distance information and electromagnetic upper limits from multiple surveys for multiple events, and self-consistently accounts for finite sky-coverage and probability of astrophysical origin. The framework is agnostic to the brightness evolution assumed and can account for multiple electromagnetic passbands simultaneously. Our analyses highlight the import…

通过信息几何推断未报告的测量不确定性

Inferring Unreported Measurement Uncertainties via Information Geometry in Astrophysics

本文提出FIMER框架，通过信息几何方法从异质天文数据中重建有效的测量不确定性，以提高统计推断的可靠性。

汤姆逊散射三轴椭球的偏振特性

Polarization Properties of Thomson-Scattering Triaxial Ellipsoids

本研究系统研究球体及推广至三轴椭球的汤姆逊散射连续谱偏振，揭示强变形球体偏振的非单调依赖等特性，为限制天体物理瞬变源几何提供物理解释，计算结果将公开。

偏振与偏振测量

Polarization and Polarimetry: A Review

偏振是光的基本性质，并且从根本上与辐射源的内部几何形状相关联。偏振测量补充了对辐射源的光度、光谱和成像分析，并使多个天体物理学发现成为可能。在这篇文章中，我回顾了（i）偏振的物理基础：电磁波、光子和参数化;（ii）偏振的天体物理学来源：散射、同步辐射、有源介质、塞曼效应、戈德赖希-凯拉夫斯效应和汉勒效应，以及偏振与物质之间的相互作用（如双折射、法拉第旋转或法拉第-费米效应）;（iii）观测方法：天空几何学、大气和仪器极化的影响、极化统计学以及无线电、光学和X/伽马波长的观测技术;及（iv）天文偏振测量的科学个案：太阳及恒星物理学、行星系统天体、星际物质、天体生物学、天文微波激射器、天文雷达、银河磁场、伽马射线暴、活动星系核及宇宙微波背景辐射。

利用非偏振天空校准米波段射电干涉阵列仪器偏振的形式化方法：基于MWA观测的演示

A Formalism for Calibrating the Instrumental Polarization of Radio Interferometric Arrays at Meter Wavelengths using Unpolarized Sky: A Demonstration using the MWA Observations

本文提出一种利用非偏振天空模型校准米波段射电干涉阵列仪器偏振的新形式化方法，通过主波束引起的表观偏振避免依赖明亮偏振校准源且不受电离层法拉第旋转影响，并用MWA观测验证了其准确性。