Could an isolated neutron star look like an AGN?
At a high level, one can consider an isolated neutron star, floating through interstellar space as gathering up material that it encounters and building up clouds of this material in its vicinity. If some of that material is drawn in to the neutron star by gravity, then we have the standard model of an accretion process onto a neutron star, which is known to emit x-rays.
The net result is an x-ray source that will be emitting x-rays into the clouds of material that it has gathered from the interstellar medium.
This, in many ways, is completely analogous to the model of an active galactic nucleus (AGN) drawing material in from its surrounding galaxy, which will have the same type of material as our isolated neutron star.
Therefore, I am suggesting a conjecture that in some cases, entities that have been identified as AGN’s may, in fact, under closer scrutiny, turn out to be isolated neutron stars that have collected interstellar material that has formed an accretion disk that supplies material to the neutron star. It may also have formed a surrounding torus of interstellar gas and dust, which is illuminated by the x-rays from the accretion process. In addition, jets may be formed along the magnetic field polar axis of the neutron star, since that will be the path of the accreting material, which will be in the form of electrons and ionized particles spiraling in around the magnetic field lines.
In terms of the source of the jets, the Crab Pulsar provides observational evidence of jets emerging from a neutron star pulsar. The origin of jets is a current topic of general research, however, it is mentioned here to demonstrate the observations of jets emerging from isolated neutron star activity, at least in the case of an isolated neutron star pulsar.
Since an isolated neutron star that is not a pulsar has yet to be officially observed, we can only conjecture that it is feasible that such an isolated neutron star object in the process of long term collection of interstellar material may produce jets as a result of the accretion of collected interstellar material.