透镜化热点图像中的传播延迟与区域强度变化

中文摘要 AI 辅助

传播延迟导致在单一观测者时间记录的图像混合了源演化不同阶段发出的辐射。总强度的可比变化可能伴随着视在图像尺寸的明显甚至相反的变化。利用区域强度、质心和协方差，我们应用总协方差定律，将区域强度权重的变化与内部宽度和质心分离的变化分离开来。对沿规定强场轨迹运动的有限高斯热点的射线追踪模拟显示，两个事件在屏幕积分强度上具有可比的衰减，但在二阶矩尺寸上却呈现相反的变化。在收缩事件中，区域权重偏离平衡；在膨胀事件中，即使质心相互接近，区域权重也趋向平衡。因此，微分传播延迟通过在不同空间分离的图像区域之间重新分配强度，驱动了这些相反的尺寸响应。

英文摘要

Propagation delays cause an image recorded at a single observer time to combine radiation emitted at different stages of the source evolution. Comparable changes in total intensity can accompany distinct and even opposite changes in apparent image size. Using regional intensities, centroids, and covariances, we apply the law of total covariance to separate changes in regional intensity weights from changes in internal widths and centroid separation. Ray tracing simulations of a finite Gaussian hotspot moving along a prescribed strong field trajectory show two events with comparable attenuation in screen integrated intensity but opposite changes in second moment size. In the contracting event, the regional weights move away from balance; in the expanding event, they move toward balance even as the centroids approach each other. Differential propagation delays therefore drive these opposite size responses by redistributing intensity between spatially separated image regions.

发表机构

• School of Physics and Astronomy, China West Normal University（西南师范大学物理与天文学院）

机构由 AI 辅助整理，请以论文原文为准。