A compact core-jet structure in the changing-look Seyfert NGC 2617
  The nearby face-on spiral galaxy NGC 2617 underwent an unambiguous
'inside-out' multi-wavelength outburst in Spring 2013, and a dramatic Seyfert
type change probably between 2010 and 2012, with the emergence of broad optical
emission lines. To search for the jet activity associated with this variable
accretion activity, we carried out multi-resolution and multi-wavelength radio
observations. Using the very long baseline interferometric (VLBI) observations
with the European VLBI Network (EVN) at 1.7 and 5.0 GHz, we find that NGC 2617
shows a partially synchrotron self-absorbed compact radio core with a
significant core shift, and an optically thin steep-spectrum jet extending
towards the north up to about two parsecs in projection. We also observed NGC
2617 with the electronic Multi-Element Remotely Linked Interferometer Network
(e-MERLIN) at 1.5 and 5.5 GHz, and revisited the archival data of the Very
Large Array (VLA) and the Very Long Baseline Array (VLBA). The radio core had a
stable flux density of about 1.4 mJy at 5.0 GHz between 2013 June and 2014
January, in agreement with the expectation of a supermassive black hole in the
low accretion rate state. The northern jet component is unlikely to be
associated with the 'inside-out' outburst of 2013. Moreover, we report that
most optically selected changing-look AGN at z<0.83 are sub-mJy radio sources
in the existing VLA surveys at 1.4 GHz, and it is unlikely that they are more
active than normal AGN at radio frequencies.
