Further evidence for a quasar-driven jet impacting its neighbour galaxy:
  The saga of HE0450-2958 continues
  HE0450-2958, an interacting quasar-starburst galaxy pair at $z$ = 0.285, is
one of the best known examples of strong star formation activity in the
presence of a quasar-driven jet. We present new multi-band JVLA-imaging
covering 1 to 6 GHz and reaching an angular resolution of up to
$0{}_{{}^.}^{"}6$ (a 6-fold improvement over existing radio data). We confirm
the previous detection of a spatially extended radio component around the
quasar indicating that there is on-going star formation activity in the quasar
host galaxy. For the first time, we directly detect a jet-like bipolar outflow
from the quasar aligned with its companion star-forming galaxy (SFG) and
several blobs of ionized gas in its vicinity identified in previous studies.
Within the companion SFG we find evidence for a flattening of the synchrotron
spectral index towards the point of intersection with the jet axis, further
suggesting that the outflow may actually be impacting its interstellar medium
(ISM). We discuss two possible mechanisms that could have triggered the
starburst in the companion SFG: a wet-dry merger with the quasar and
jet-induced star formation. While triggering through interaction-driven gas
dynamics cannot be excluded with current data, our new observations make
HE0450-2958 a strong candidate for jet-induced star formation, and one of the
rare links between local systems (like Minkowski's Object or Centaurus A) and
the high-z regime where radio-optical alignments suggest that this phenomenon
could be more common.
