RM020
e-EVN: EA077A, RSB04, RM020
The Lorentz factors of the jets in relativistic tidal disruption events (TDEs) have previously been estimated from theoretical modelling of the observed spectra. However, such estimates depend heavily on model assumptions. We have been conducting EVN astrometric monitoring of the relativistic TDE AT2022cmc since its discovery in early 2022. Our preliminary results appear to show the first direct evidence of a positional shift in a TDE jet, which would constrain the average Lorentz factor over the 1.5 years of monitoring to 15 ± 4. However, the final epoch of data was subject to significant atmospheric phase gradients. While the use of the two phase reference calibrators allowed us to correct for these phase gradients, our results are highly dependent on the accuracy of this correction. We therefore request an additional epoch of data to confirm our preliminary results, providing the first robust measurement of the proper motion of a TDE jet.
Observation pages at the EVN archive:
Context for this dataThis data is part of the archive of VLBI data maintained by JIVE on behalf of the EVN, a network of radio telescopes located primarily in Europe and Asia, with additional antennas in South Africa. The EVN archive itself has the DOI https://doi.org/10.17616/R3Z197