Activity restart - a key to explaining the morphology of J1211+743
  J1211+743 is a giant radio galaxy with a one-sided jet and two asymmetric
lobes, one of which is of Fanaroff-Riley (FR) type II with a hotspot and the
other is a diffuse relic devoid of a hotspot. The jet points towards the latter
lobe, which is difficult to explain in a standard way within the double-lobed
radio source paradigm. Here, I propose to assume that the nucleus of J1211+743
has undergone a re-ignition of activity and its lobes, presumably both
originally of FR II type, represent an earlier active phase, while the jet
represents the current one. The asymmetry of the lobes is a consequence of the
orientation of the source combined with an activity switch-off that occurred
between two active periods. The relic lobe is on the near side with regard to
the observer, whereas the radiation from the far-side lobe arrives
significantly later owing to its longer distance to the observer. The far-side
lobe is thus perceived to have not yet decayed. On the other hand, the jet
behaves in a standard way, i.e. its projected orientation reflects the near
side of the source. Hence, we are able to explain why the location of the relic
lobe correlates with the direction of the jet.
