The IceCube event IceCube-170922A appears to originate from the BL Lac object TXS 0506+056. Despite many other BL Lac objects showing similar properties as TXS 0506+056, such as multiwavelength variability or a curved jet, so far, only TXS 0506+056 has been identified as neutrino emitter. The pc-scale jet of TXS 0506+056 might thus reveal special properties. We performed a detailed study of radio images of the jet obtained at 15 GHz (16 VLBA observations between Jan. 2009 and May 2018). Our results suggest that the jet is extremely strongly curved and most likely observable under a very special viewing angle of close to zero. We might see interaction between jet features which cross each others' paths. An alternative, less likely scenario is, that we do not see the signature of one but of two jets. In both cases, we find evidence for a collision of jetted material. We propose that the enhanced neutrino activity during the neutrino flare in 2014 - 2015 and the single EHE neutrino IceCube-170922A were generated by a cosmic collision within TXS 0506+056. This seems to be the first time, that a collision within a jet is reported. And obviously, this is the first time that the detection of a cosmic neutrino can be traced back to a cosmic jet-collision.
Memorie della Societa Astronomica Italiana
- Pub Date:
- black hole physics;
- techniques: interferometric;
- BL Lacertae objects: individual: TXS 0506+056