Is an obscured AGN at the centre of the disk galaxy IC 2497 responsible
  for Hanny's Voorwerp?
  We present the results of VLBI and MERLIN observations of the massive disk
galaxy IC 2497. Optical observations of IC 2497 revealed the existence of a
giant emission nebula "Hanny's Voorwerp" in the proximity of the galaxy.
Earlier short-track 18 cm observations with e-VLBI at 18 cm, detected a compact
radio component (C1) at the centre of IC 2497. The brightness temperature of C1
was measured to be greater than 4E5 K. Deeper, long-track e-VLBI observations
presented here, re-confirm the existence of C1 but also reveal the existence of
a second compact component (C2) located about 230 milliarcseconds to the
North-East of C1. The brightness temperature of C2 is measured to be greater
than 1.4E5 K, suggesting that both components may be related to AGN activity
(e.g. a radio core and jet hotspot). Lower resolution 18cm MERLIN observations
show both components. C1 is shown to be compact with a slight elongation along
the direction of Hanny's Voorwerp, and C2 shows a lot of extended emission in
an almost perpendicular direction to the direction of the Voorwerp. Our results
continue to support the hypothesis that IC 2497 contains an Active Galactic
Nucleus (AGN), and that a jet associated with this AGN clears a path that
permits ionising radiation from the AGN to directly illuminate the emission
nebula.
