DOI

https://doi.org/10.48717/pexg-3g71

Project

EG112

Title

e-EVN: EG112

Abstract

The current cosmological structure formation models predict that galaxies grow through frequent mergers. During these events activity in the nuclei of the merging galaxies can be triggered. Either binary AGN or in the case of unequal mass mergers recoiling AGN can form. However, these objects are observationally elusive targets. Kim et al. (2020) reported a double-peaked broad line system in a merging galaxy. While the binary AGN model seems to be hard to reconcile with the observed velocity shifts between the lines, a recoiling AGN may explain the observed characteristics. However, an alternative scenario containing a single AGN with a thick accretion disk can also explain the results. This model could also account for extended radio emission. A radio feature approx. 2 arcsec from the optical position is detected with the FIRST survey. We propose an L-band EVN+e-MERLIN observation to determine if it contains a compact radio AGN, its accurate coordinates and to map the 100-mas radio structure. Thus we can discriminate between the above models: it is either cospatial with the optical position thus favors the accretion disk origin of the broad lines, or the radio core is offset strengthening a recoiling AGN scenario.