2024ApJ...965..167L

X-ray emission is an important tracer of stellar magnetic activity. We carried out a systematic correlation analysis for the X-ray luminosity $\mathrm{log}{L}_{{\rm{X}}}$, bolometric luminosity $\mathrm{log}{L}_{\mathrm{bol}}$, and X-ray activity level $\mathrm{log}({L}_{{\rm{X}}}$/L_bol) versus the binary parameters including orbital period P, Rossby number R_O, effective temperature T_eff, metallicity [Fe/H], the surface gravity $\mathrm{log}g$, stellar mass M, and radius R, by assembling a large sample of semi-detached (EB-type) binaries with X-ray emission (EBXs). The fact that both $\mathrm{log}{L}_{{\rm{X}}}$ and $\mathrm{log}{L}_{\mathrm{bol}}$ change in accordance with $\mathrm{log}P$ indicates that X-ray emission originates from the convection zone, while $\mathrm{log}{L}_{{\rm{X}}}$ 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 $\mathrm{log}{T}_{\mathrm{eff}}$-$\mathrm{log}{L}_{{\rm{X}}}$ and M-$\mathrm{log}{L}_{{\rm{X}}}$ 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 $\mathrm{log}{T}_{\mathrm{eff}}$ 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 a similar R_O-$\mathrm{log}({L}_{{\rm{X}}}/{L}_{\mathrm{bol}})$ 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 $\mathrm{log}{L}_{{\rm{X}}}$ and $\mathrm{log}({L}_{{\rm{X}}}$/L_bol).