标题： 强耀斑在四个耀变体中的频率依赖时间延迟，来自Metsahovi和UMRAO监测数据库 显示英文标题

标题： Frequency-dependent time delays for strong outbursts in four blazars from the Metsahovi and UMRAO monitoring databases

摘要： 密歇根大学射电天文台和梅塔霍维射电天文台的联合数据为我们提供了活动星系核的射电光变曲线，这些星系核被两个天文台从4.8到37 GHz监测，时间跨度长达约25年。 我们在此考虑了四个伽马射线耀变体的复合光变曲线，这些耀变体在两个天文台几乎连续被监测：0458-020、0528+134、1730-130和2230+114。 我们使用高斯模型拟合将这四个耀变体光变曲线中最显著的爆发分解为单独的组分，并将这些组分的爆发时刻、振幅和半宽度作为频率的函数进行估计。 我们试图区分“核心爆发”，它们表现出与频率相关的时延，并与核心变亮有关，以及“喷流爆发”，它们在所有频率上几乎同步出现，并伴随着新喷流组分的出现及其后续演化。 可用的43 GHz VLBA图像仅允许我们识别一个纯核心爆发（在2230+114）和一个纯喷流爆发（0458-020）。 分析的大多数爆发是混合型的，即它们表现出与频率相关的时延（即它们是光学厚的），并且与新喷流组分的最终出现有关。 喷流和混合爆发的峰值可能对应于新喷出组分变得完全光学薄的时刻。 这些时刻还伴随着喷出组分角速度的显著增加。 有证据表明，2230+114的爆发每隔8.0±0.3年重复一次，在每个准周期性的八年周期中，单个子爆发的位置被保留下来，尽管它们的振幅变化超过两倍。 显示英文摘要

摘要： The combined data of the University of Michigan Radio Astronomy Observatory and Metsahovi Radio Observatory provide us with radio light curves for Active Galactic Nuclei monitored by both observatories from 4.8 to 37 GHz covering time intervals up to ~25 years. We consider here such composite light curves for four gamma-ray blazars that have been nearly continuously monitored at both observatories: 0458-020, 0528+134, 1730-130 and 2230+114. We have decomposed the most prominent outbursts in the light curves of these four blazars into individual components using Gaussian model fitting, and estimated the epochs, amplitudes, and half-widths of these components as functions of frequency. We attempt to distinguish "core outbursts", which show frequency-dependent time delays and are associated with brightening of the core, from "jet outbursts", which appear nearly synchronously at all frequencies and are accompanied by the emergence of new jet components and their subsequent evolution. Available 43 GHz VLBA images allow us to identify only one pure core outburst (in 2230+114) and one pure jet outburst (0458-020). Most of the outbursts analyzed are mixed, in the sense that they display frequency-dependent time delays (i.e., they are optically thick) and are associated with the eventual emergence of new jet components. The maxima of the jet and mixed outbursts probably correspond to epochs when newly ejected components become fully optically thin. These epochs are also marked by a significant increase in the angular velocities of the ejected components. There is evidence that the outbursts in 2230+114 repeat every 8.0+-0.3 years, with the positions of individual sub-outbursts being preserved from one quasi-periodic eight-year cycle to another, even though their amplitudes vary by more than a factor of two.