Print Email Facebook Twitter From binary to singular Title From binary to singular: The AGN PSO J334.2028+1.4075 under the high-resolution scope Author Benke, P. (Max-Planck-Institute for Radio Astronomy; University of Würzburg) Gabányi, K. E. (Eötvös University; Konkoly Observatory Hungarian Academy of Sciences) Frey, S. (Konkoly Observatory Hungarian Academy of Sciences; Eötvös University) An, T. (Chinese Academy of Sciences) Gurvits, L. (TU Delft Astrodynamics & Space Missions; Joint Institute for VLBI ERIC) Kun, E. (Konkoly Observatory Hungarian Academy of Sciences; MTA Centre of Excellence; Ruhr-Universität Bochum) Mohan, P. (Chinese Academy of Sciences) Paragi, Z. (Joint Institute for VLBI ERIC) Ros, E. (Max-Planck-Institute for Radio Astronomy) Date 2023 Abstract Context. PSO J334.2028+1.4075 (PSO J334) is a luminous quasar located at redshift z = 2.06. The source gained attention when periodic flux density variations were discovered in its optical light curve. These variations were initially interpreted as the variability due to the orbital motion of a supermassive black hole binary (SMBHB) residing in a single circumbinary accretion disk. The orbital separation was determined to be 0.006 pc with an in-spiral time of 7 yr in the rest frame of PSO J334. These findings suggested the quasar could be in the gravitational wave emitting phase of its merger and so extended multiwavelength observations were commenced. However, subsequent observations provided evidence against the binary hypothesis as no optical periodicity was found on extended time baselines. On the other hand, detailed radio analysis with the Karl G. Jansky Very Large Array (VLA) and the Very Long Baseline Array (VLBA) revealed a lobe-dominated quasar at kiloparsec scales, and possibly a precessing jet, which could retain PSO J334 as a binary SMBH candidate. Aims. We aim to study both the large- and small-scale radio structures in PSO J334 to provide additional evidence for or against the binary scenario. Methods. We observed the source at 1.7 GHz with the European Very Long Baseline Interferometry Network (EVN), and at 1.5 and 6.2 GHz with the VLA, at frequencies that complement the previous radio interferometric study. Results. Our images reveal a single component at parsec scales slightly resolved in the southeast-northwest direction and a lobe-dominated quasar at kiloparsec scales with a complex structure. The source morphology and polarization in our VLA maps suggest that the jet is interacting with dense clumps of the ambient medium. While we also observe a misalignment between the inner jet and the outer lobes, we suggest that this is due to the restarted nature of the radio jet activity and the possible presence of a warped accretion disk rather than due to the perturbing effects of a companion SMBH. Conclusions. Our analysis suggests that PSO J334 is most likely a jetted active galactic nucleus with a single SMBH, and there is no clear evidence of a binary SMBH system in its central engine. Subject Galaxies: activeGalaxies: jetsPolarizationTechniques: high angular resolutionTechniques: interferometric To reference this document use: http://resolver.tudelft.nl/uuid:c4c10339-b4c1-4195-aa25-2c33d9b58516 DOI https://doi.org/10.1051/0004-6361/202346904 ISSN 0004-6361 Source Astronomy & Astrophysics, 677 Part of collection Institutional Repository Document type journal article Rights © 2023 P. Benke, K. E. Gabányi, S. Frey, T. An, L. Gurvits, E. Kun, P. Mohan, Z. Paragi, E. Ros Files PDF aa46904_23.pdf 8.41 MB Close viewer /islandora/object/uuid:c4c10339-b4c1-4195-aa25-2c33d9b58516/datastream/OBJ/view