Optically Overluminous Tidal Disruption Events: Outflow Properties and Implications for Extremely Relativistic Disruptions

Recent studies suggest that tidal disruption events (TDEs) with off-axis jets may manifest as optically overluminous events. To search for jet signatures at late times, we conducted radio observations of eight such optically overluminous (M_g,peak < −20.8 mag) TDEs with the Very Large Array. We detect radio counterparts in four events. The observed radio luminosities (L_{6 GHz} ∼ 10³⁸-10³⁹ erg s⁻¹) are two orders of magnitude lower than those of on-axis jetted TDEs, and we find no evidence for off-axis jets within a rest-frame time of 3 yr. Two of them (AT2022hvp and AT2021aeou) exhibit evolving radio emission, consistent with synchrotron emission from non-relativistic outflows launched near the time of first optical light. Two events (AT2020ysg and AT2020qhs) show no statistically significant variability, which can be attributed to either non-relativistic outflows or pre-existing active galactic nuclei. Compared to a control sample of fainter TDEs with M_g,peak > −20.5 mag observed at similar rest-frame timescales (t_rest ∼ 1.5 yr), our sample shows systematically more luminous radio emission, suggesting that optically overluminous TDEs may launch more powerful prompt non-relativistic outflows. We speculate that strong general relativistic effects near high-mass black holes (M_BH ∼ 10⁸ M_⊙) may play a key role. These findings motivate further investigation into the nature of relativistic disruptions around massive black holes and the physical conditions necessary for jet formation.