English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The search and study of close pairs of supermassive black holes (SMBHs) isimportant in the study of galaxy mergers which can possibly trigger activegalactic nucleus (AGN) activity, and in the context of their evolution into thegravitational wave emitting regime. The quasar SDSS~J1048+0055 was identifiedas a SMBH binary candidate based on the observed double-peaked\OIII$\lambda\lambda$4959,5007 emission lines and two distinct radio componentsseparated by $\sim 20$~pc \citep{2004ApJ...604L..33Z}. To ascertain the binarynature of this source, we analyzed multi-frequency, multi-epoch very longbaseline interferometry (VLBI) data to investigate its pc-scale radioproperties. The source shows double components with the western feature beingbrighter than the eastern one. This brighter component has a brightnesstemperature of $\sim 10^{10}$~K, spectral index of $\alpha = -0.09 \pm 0.09$(flat) and is indicative of mildly relativistic beaming. In contrast, the faintcomponent has a lower brightness temperature of $\sim 10^{8-9}$~K and steepspectrum. These clues are consistent with a core--jet structure, moreover, theapparent separation speed between the two components is much higher than theexpected orbital motion in a binary SMBH. Thus the present study excludes theassociation of the two VLBI components with the cores of a SMBH binary,although the SMBH binary possibility (e.g., a pair of radio-loud andradio-quiet AGNs) is not fully ruled out. In the single active galactic nucleus(AGN) scenario, the double-peaked optical emission lines can originate from thejet interacting with the narrow-line region as indicated by a change in the jetdirection at $\sim$ 140 pc.

Jet-powered Outflows in Supermassive Black Hole Binary Candidate SDSS J1048+0055