A single radio-emitting nucleus in the dual AGN candidate NGC 5515
  The Seyfert galaxy NGC 5515 has double-peaked narrow-line emission in its
optical spectrum, and it has been suggested that this could indicate that it
has two active nuclei. We observed the source with high resolution Very Long
Baseline Interferometry (VLBI) at two radio frequencies, reduced archival Very
Large Array data, and re-analysed its optical spectrum. We detected a single,
compact radio source at the position of NGC 5515, with no additional radio
emission in its vicinity. The optical spectrum of the source shows that the
blue and red components of the double-peaked lines have very similar
characteristics. While we cannot rule out unambiguously that NGC 5515 harbours
a dual AGN, the assumption of a single AGN provides a more plausible
explanation for the radio observations and the optical spectrum.
