论文标题
F-G-K恒星中CA和H $α$色球排放之间的关系：恒星丝的指示？
Relationship between Ca and H$α$ chromospheric emission in F-G-K stars: indication of stellar filaments?
论文作者
论文摘要
在太阳能型恒星中报道了H $α$和CA II色球排放之间的不同关系。特别是，这两条线的排放时间序列显然是恒星的抗相关性，与在太阳上观察到的相反。我们的目标是使用互补标准更详细地表征这些关系，并限制解释观察结果所必需的细丝和份量的特性。我们分析了441个F-G-K恒星的H $α$和CA II排放的平均水平和可变性，特别注意其在短时间和长时间标准上的（反）相关性。我们还针对不同假设的材料和细丝特性计算了合成H $α$和CA II时间序列，并将其与观测值进行了比较。即使在允许不同的恒星的不同H $α$和CA II排放关系时，我们也无法找到单独的算法属性，即使允许不同的H $α$和CA II排放关系，也可以同时在所有时间尺度上复制观测。我们还指定了这两个索引的平均活性水平之间的复杂和令人惊讶的关系，尤其是对于低活动性恒星。我们得出的结论是，单独的毛口不可能解释Ca II和H $α$排放之间观察到的各种关系，并且存在其他现象（如细丝）的存在可能有助于将模型与观测值调和。
Different relationships between the H$α$ and Ca II chromospheric emissions have been reported in solar-type stars. In particular, the time-series of emissions in these two lines are clearly anti-correlated for a few percent of the stars, contrary to what is observed on the Sun. Our objective is to characterise these relationships in more detail using complementary criteria, and to constrain the properties of filaments and plages that are necessary to explain the observations. We analysed the average level and variability of the H$α$ and Ca II emission for 441 F-G-K stars, paying particular attention to their (anti-)correlations on both short and long timescales. We also computed synthetic H$α$ and Ca II time-series for different assumptions of plage and filament properties and compared them with the observations. We were not able to find plage properties that, alone, are sufficient to reproduce the observations at all timescales simultaneously, even when allowing different H$α$ and Ca II emission relationships for different stars. We also specified the complex and surprising relationship between the average activity levels of both indexes, in particular for low-activity stars.We conclude that plages alone are unlikely to explain the observed variety of relationships between Ca II and H$α$ emission, and that the presence of other phenomena like filaments may help to reconcile the models with observations.
