Landing page for project EA059

Supermassive black hole (SMBH) binary is expected near the final stages of galaxy mergers in hierarchical models of cosmological structure formation. They are defined by a pc-scale or smaller separation which can interestingly be (only) resolved with the VLBI technique. There are currently only two strong candidate detections 0402+379 and recently, NGC7674 (Mrk533). NGC7674 is a nearby spiral galaxy; previous VLBI images at 15GHz detected two compact components, putative cores, with 4-5sigma (Kharb et al. 2017). We propose the EVN observations of this source at 8 and 22 GHz to verify the reported SMBH binary scenario. Once confirmed, this source will be the first sub-pc separation SMBH binary directly detected with radio VLBI imaging, and also the first close SMBH binary discovered in a spiral host galaxy. Expected outcomes in addition to the possible confirmation include inference of possible faint jet(s) which may reinforce the proposed binary scenario, or rule out the binary model thus open avenues to alternate interpretations in terms of a single AGN with core-jet or double hot spots.

This data is part of the archive of VLBI data maintained by JIVE on behalf of the EVN, a network of radio telescopes located primarily in Europe and Asia, with additional antennas in South Africa. The EVN archive itself has the DOI https://doi.org/10.17616/R3Z197