发表机构
ASTRON, Netherlands Institute for Radio Astronomy（荷兰射电天文研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出框架和python包swabs预测恒星II/III型射电暴形态，发现活跃恒星日冕导致延迟增加、漂移率变浅、持续时间延长，与太阳射电暴差异显著。
AI 中文摘要
大量的观测工作已投入到识别太阳II型和III型射电暴的恒星类似物上，这些射电暴分别是日冕物质抛射和快速电子束在日冕和风中传播时产生的等离子体辐射。这些射电暴对环境等离子体的敏感性及其与高能瞬态粒子通量的关联，使其成为系外太阳系空间天气的强大诊断工具。然而，对恒星射电暴的分析往往依赖于这样的假设：产生这些射电暴的恒星日冕与太阳日冕相似，或者不稳定性条件与太阳相同。由此进一步假设恒星射电暴的形态与太阳射电暴非常相似。我引入了一个简单的框架和python包swabs，用于预测恒星II型和III型射电暴的形态，以理解它们可能如何偏离太阳射电暴的形态。我给出了两颗研究较为充分的活跃恒星在10--170 MHz范围内的射电暴预期：M矮星AD Leonis和G矮星EK Draconis。这些恒星的结果表明，活跃恒星的日冕可能导致射电暴与太阳射电暴相比具有（1）到达观测波段的延迟时间显著增加，（2）漂移率更浅，（3）持续时间更长。炽热且快速的风也可能抑制II型和III型射电暴的发展，无论阿尔芬速度如何。非等温风会减少这种抑制，但可能增加射电暴的延迟和持续时间。这项工作表明，恒星射电暴可能与其太阳类似物有根本性的差异。在我们如何进行恒星射电暴搜索以及如何评估导致射电暴结构的日冕条件时，需要考虑这些差异。
英文摘要
Significant observational effort has been spent on identifying stellar analogues to solar type II and III bursts, which are plasma emission that is produced when coronal mass ejections and fast electron beams, respectively, propagate through the corona and wind. The sensitivity of these bursts to ambient plasma and their association with energetic transient particle flux makes them powerful diagnostics of exo-solar space weather. However, analyses of stellar bursts often rely on the assumption that the coronae of the stars that produce them are similar to the solar corona or that the instability requirements are the same as for the Sun. By extension, the assumption is that the forms of stellar bursts are very similar to that of solar bursts. I introduce a simple framework and the python package, swabs, to predict the shapes of stellar type II and III bursts to understand how they may deviate from the shapes of solar bursts. I present the burst expectations in the range of 10--170 MHz for two well-studied active stars: the M dwarf AD Leonis, and the G dwarf EK Draconis. The results for these stars suggest that the coronae of active stars may lead to bursts that have substantially (1) delayed arrival times to the observing band, (2) shallower drift rates, and (3) longer durations than solar bursts. The hot and fast winds may also inhibit the development of type~II and III bursts, regardless of the Alfvén speed. Non-isothermal winds reduce this inhibition, but may increase the delays and durations of the bursts. This work demonstrates that stellar bursts may deviate radically from their solar analogues. These deviations need to be considered in how we conduct searches for stellar bursts and how we evaluate the coronal conditions that cause the burst structures.
Comments10 pages, 7 figures, 4 tables
DOI：10.1051/0004-6361/202660595
