UBV light curves of DQ Tau and UZ Tau E

Further, we do not detect any correlation between CIV flux and phase. For both stars the appearance of the CIV line is similar to that of single Classical T Tauri Stars (CTTSs), despite the lack of stable long-lived circumstellar disks. However, unlike the case in single CTTSs, the narrow and broad components of the CIV lines are uncorrelated, and we argue that the narrow component is powered by processes other than accretion, such as flares in the stellar magnetospheres and/or enhanced activity in the upper atmosphere.

We find that both stars contribute equally to the narrow component CIV flux in DQ Tau, but the primary dominates the narrow component CIV emission in UZ Tau E. The CIV broad component flux is correlated with other accretion indicators, suggesting an accretion origin. However, the line is blueshifted, which is inconsistent with its origin in an infall flow close to the star. It is possible that the complicated geometry of the region, as well as turbulence in the shock region, are responsible for the blueshifted line profiles.