发表机构
Astronomical Institute of the Academy of Sciences; National Astronomical Observatory of Japan; University of Wroclaw（科学院天文研究所; 日本国立天文台; 弗罗茨瓦夫大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文利用似然自由贝叶斯推断结合前向辐射传输模型，从IRIS Mg II k临边光谱中推断太阳针状体的群体级特性，并约束其主导观测变异性和高度依赖性的有效参数。
AI 中文摘要
太阳针状体在临边观测中普遍存在且强烈重叠，这使单个事件的解释变得复杂。我们旨在利用一个明确考虑视线叠加和仪器效应的前向模型，从IRIS Mg~II~k临边光谱推断针状体的群体级特性。我们构建了一个随机的三维针状体群体模型，并通过辐射传输合成Mg II k光谱，包括仪器退化和光子噪声。随后，我们利用基于近似贝叶斯计算和自适应群体蒙特卡洛采样的似然自由贝叶斯推断，约束描述底层针状体群体的超参数，通过主成分汇总统计在临边以上五个高度处比较观测和模拟数据集。推断出的后验分布有效约束了主导观测到的Mg II k变异性和高度依赖性的针状体群体级特性。这些约束为将临边光谱学与即将到来的色球-日冕界面光谱偏振诊断联系起来提供了途径。
英文摘要
Solar spicules are ubiquitous and strongly overlapping in off-limb observations, which complicates the interpretation of individual events. We aim to infer population-level properties of spicules from IRIS Mg~II~k off-limb spectra using a forward model that explicitly accounts for line-of-sight superposition and instrumental effects. We construct a stochastic three-dimensional spicule-population model and synthesize Mg II k spectra with radiative transfer, including instrumental degradation and photon noise. We then constrain the hyperparameters that describe the underlying spicule population with likelihood-free Bayesian inference based on approximate Bayesian computation and an adaptive population Monte Carlo sampler, comparing observed and simulated datasets through principal-component summary statistics at five heights above the limb. The inferred posterior constrains effective population-level properties of the spicules that dominate the observed Mg II k variability and height dependence. These constraints provide a route to connect off-limb spectroscopy with forthcoming spectropolarimetric diagnostics of the chromosphere-corona interface.
Comments13 pages, 9 figures, accepted for publication in Astronomy & Astrophysics
