DOI

https://doi.org/10.48717/vxqm-4g24

Project

EU003

Title

{EU003A}

Abstract

VLBI observations of group- and cluster-dominant elliptical galaxies have shown that in ~30% of cases, the currently active jets are strongly (>45 degree) misaligned with respect to the X-ray cavities produced by past outbursts. An extreme example is NGC 5044, the central elliptical of the X-ray brightest group in the sky, where the orientation of the parsec-scale radio jets is orthogonal to that of the two pairs of cavities, implying a 90 degree change in jet direction over only ~1 Myr. Recent C-band, X-band, and K-band VLBA data suggest the presence of a compact (0.4 pc separation, or 3~mas) binary AGN at the heart of the system, potentially explaining the misalignment; the older X-ray cavities may have been excavated by jets from the secondary core during a past outburst. If confirmed, this will be the tightest known (and VLBI-imaged) binary AGN system by an order of magnitude, with significant implications well beyond NGC 5044. We request sensitive EVN X & K band observations to image and measure the spectral index of the candidate binary AGN at sub-pc resolution, allowing us to confirm this exciting discovery.