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Abstract We present detailed radio observations of the mid-infrared (MIR) tidal disruption event (TDE) WTP14adeqka. We detect rising radio emission starting ≈4 yr after the discovery of the MIR emission (and about 2 yr after its peak), peaking at ≈6.5 yr and declining thereafter, reminiscent of the delayed radio emission recently identified in optically discovered TDEs. The peak radio luminosity,νLν ≈ 2 × 1039erg s−1, is comparable to the brightest radio emission in optical TDEs. Multifrequency radio observations at 8.9 and 9.7 yr reveal a nonrelativistic outflow with a mean expansion velocity of ≈0.022c(for an assumed launch at the time of disruption) and an energy of ≈1049.8erg, about an order of magnitude larger than in typical optical TDEs. More importantly, Very Long Baseline Array (VLBA) observations at the same epochs directly resolve the radio source and reveal an increase in the major axis of a slightly elliptical Gaussian from 0.11 to 0.13 pc (with no apparent astrometric shift), corresponding to an expansion velocity of ≈0.049c, and a potentially delayed launch by about 2 yr. The VLBA size measurements rule out an off-axis jet launched at the time of disruption, which would be ≳pc on these timescales; the possibility of a delayed jet can be evaluated with future VLBA observations. We conclude that MIR TDEs can launch energetic, nonrelativistic outflows. Ongoing radio observations of the full MIR TDE sample will reveal whether this behavior is ubiquitous.
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This content will become publicly available on November 5, 2026
Optically Overluminous Tidal Disruption Events: Outflow Properties and Implications for Extremely Relativistic Disruptions
Abstract 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 (Mg,peak < −20.8 mag) TDEs with the Very Large Array. We detect radio counterparts in four events. The observed radio luminosities (L6 GHz ∼ 1038–1039erg 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 withMg,peak > −20.5 mag observed at similar rest-frame timescales (trest ∼ 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 (MBH ∼ 108M⊙) 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.
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- PAR ID:
- 10707382
- Author(s) / Creator(s):
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Publisher / Repository:
- American Astronomical Society
- Date Published:
- Journal Name:
- The Astrophysical Journal
- Volume:
- 993
- Issue:
- 2
- ISSN:
- 0004-637X
- Page Range / eLocation ID:
- 198
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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