引力透镜类星体中的吸积盘尺寸与温度分布：近红外微引力透镜对薄盘理论的挑战
Accretion Disk Sizes and Temperature Profiles in Lensed Quasars: NIR Microlensing Challenges Thin Disk Theory
浏览论文内容
中文总结 AI 辅助
该研究利用7个引力透镜系统21个像对的近红外同质观测数据，将类星体吸积盘尺寸测量扩展至14光日，发现外盘尺寸更大、温度梯度更陡，以98%置信度拒绝薄盘理论的对数斜率预测，挑战了薄盘理论。
中文摘要 AI 辅助
对类星体吸积盘尺寸和温度梯度的微引力透镜与反响映射测量结果，与薄盘理论的预测存在不一致。此前的微引力透镜研究结果依赖于异质的波长覆盖范围，主要来自小样本的紫外宽发射线（BELs），平均仅能探测到吸积盘约≤5光日的典型半径。我们利用一组同质的引力透镜类星体近红外（NIR）观测数据的微引力透镜估计值（共7个透镜系统的21个像对），将吸积盘尺寸测量范围扩展至14光日。本分析采用窄发射线（NELs），相较于宽发射线核心，其能提供更可靠的无微引力透镜的基线。我们推导了贝叶斯吸积盘尺寸估计值，这些估计值可复现从放大率图模拟得到的观测微引力透镜放大率。基于窄发射线的尺寸得出的对数斜率为p=0.68±0.23，与对应内盘区域（r≤5光日）的先前估计值一致。利用新的同质近红外数据集，我们得以探测至径向距离达14光日的区域，发现这些此前未被探索的区域中的吸积盘更大，且表现出比薄盘理论预测更陡峭的温度梯度。提升的精度使我们能以98%的置信度拒绝理论对数斜率p=4/3。任何援引宽线区（BLR）污染来解释这一差异的假说，都必须说明此类污染如何调制 underlying吸积盘，使得两者结合后在从约X射线到约5000埃的宽波长基线上呈现出对数斜率为p=0.68±0.23的幂律。
英文摘要
Microlensing and reverberation mapping measurements of quasar accretion disk sizes and temperature gradients disagree with thin disk theory predictions. Previous microlensing results rely on heterogeneous wavelength coverage -primarily UV broad emission lines (BELs) from small samples -probing the disk only out to a typical radius of $\lesssim$5 light days on average. We use microlensing estimates from an homogeneous sample of near-infrared (NIR) observations of lensed quasars (21 image-pairs from 7 lens systems) to extend disk size measurements out to 14 light days. This analysis leverages narrow emission lines (NELs), which provide a more reliable microlensing-free baseline than BEL cores. We derive Bayesian accretion disk size estimates that reproduce the observed microlensing magnifications, as simulated from magnification maps. NEL-based sizes yield a logarithmic slope of $p=0.68\pm0.23$, consistent with prior estimates corresponding to inner disk regions ($r \lesssim$5 light days). Using a new homogeneous NIR dataset that allows us to reach radial distances of up to 14 light days, we find that accretion disks in these previously unexplored regions are also larger and exhibit steeper temperature gradients than thin disk theory predicts. The increased precision allows us to reject the theoretical logarithmic slope $p=4/3$ at the 98\% confidence level. Any hypothesis invoking BLR contamination to explain this discrepancy must account for how such contamination modulates the underlying accretion disk such that the combination of both results in a power law with logarithmic slope $p=0.68\pm0.23$ across a broad wavelength baseline spanning from $\sim$X-Ray to $\sim 5000$Å.
