标题： X射线发射揭示了半分离双星的日冕活动 显示英文标题

标题： The X-ray Emission Reveals the Coronal Activities of Semi-detached Binaries

摘要： X射线辐射是恒星磁场活动的重要示踪剂。 我们系统地分析了X射线光度$\log L_{\rm X}$、总辐射通量$\log L_{\rm bol}$和X射线活动水平$\log(L_{\textrm{X}}$/$L_{\textrm{bol}})$与双星参数之间的相关性，这些参数包括轨道周期$P$、罗素数$R_{\rm O}$、有效温度$T_{\rm eff}$、金属丰度[Fe/H]和表面重力$\log g$以及恒星质量$M$和半径$R$。这项研究通过收集大量具有X射线辐射的半分离（EB型）双星样本（EBXs）来完成。 事实表明，$\log L_{\rm X}$和$\log L_{\rm bol}$都随$\log P$变化，这表明 X 射线发射起源于对流区，而$\log L_{\rm X}$与对流区面积成正比。 我们发现，具有主序星组分的EBX表现出在$\log T_{\rm eff}$-$\log L_{\textrm{X}}$和$M$-$\log L_{\textrm{X}}$关系中的先上升后下降的趋势，这与包含亚巨星和巨星组分的EBX所显示的单调递减趋势不同。 磁活动水平与$\log T_{\rm eff}$和恒星质量呈负相关。 基于磁场发电机模型，表面对流区大小和厚度的变化可以解释观测到的关系。 具有主序星组分的EBX与普拉塞佩和海达耶等星团中的双星具有相似的$R_{\rm O}$-$\log(L_{\textrm{X}}/L_{\textrm{bol}})$关系。 我们比较了EBX的X射线辐射特性与接触双星的X射线发射特性，发现EBX在$\log L_{\rm X}$和$\log(L_{\textrm{X}}$/$L_{\textrm{bol}})$的值范围更广。 显示英文摘要

摘要： X-ray emission is an important tracer of stellar magnetic activity. We carried out a systematic correlation analysis for the X-ray luminosity $\log L_{\rm X}$, bolometric luminosity $\log L_{\rm bol}$, and X-ray activity level $\log(L_{\textrm{X}}$/$L_{\textrm{bol}})$ versus the binary parameters including orbital period $P$, Rossby number $R_{\rm O}$, effective temperature $T_{\rm eff}$, metallicity [Fe/H] and the surface gravity $\log g$, and the stellar mass $M$ \& radius $R$, by assembling a large sample of semi-detached (EB-type) binaries with X-ray emission (EBXs). The fact that both $\log L_{\rm X}$ and $\log L_{\rm bol}$ change in accordance with $\log P$ indicates that X-ray emission originates from the convection zone, while $\log L_{\rm X}$ is proportional to the convection zone area. We found that EBXs with main-sequence components exhibit an upward and then a downward trend in both the $\log T_{\rm eff}$-$\log L_{\textrm{X}}$ and $M$-$\log L_{\textrm{X}}$ relations, which is different from the monotonically decreasing trend shown by EBXs containing sub-giant and giant components. The magnetic activity level is negatively correlated with $\log T_{\rm eff}$ and stellar mass. Based on the magnetic dynamo model, the variations in the size and thickness of the surface convection zones can explain the observed relations. EBXs with main-sequence components have similar $R_{\rm O}$-$\log(L_{\textrm{X}}/L_{\textrm{bol}})$ relationship to that of the binaries in the clusters as Praesepe and Hyade. We compared the X-ray radiation properties of EBXs with those of the X-ray-emitting contact binaries and found that EBXs have broader value ranges for $\log L_{\rm X}$ and $\log(L_{\textrm{X}}$/$L_{\textrm{bol}})$.