We present high angular resolution imaging (23.9×11.3 mas, 138.6×65.5 pc) of the radio-loud quasar PSO~J352.4034−15.3373 at z=5.84 with the Very Long Baseline Array (VLBA) at 1.54 GHz. This quasar has the highest radio-to-optical flux density ratio at such a redshift, making it the radio-loudest source known to date at z∼6. The VLBA observations presented here resolve this quasar into multiple components with an overall linear extent of 1.62 kpc (0.′′28) and with a total flux density of 6.57±0.38 mJy, which is about half of the emission measured at a much lower angular resolution. The morphology of the source is comparable with either a radio core with a one-sided jet, or a compact or a medium-size Symmetric Object (CSO/MSO). If the source is a CSO/MSO, and assuming an advance speed of 0.2c, then the estimated kinematic age is ∼104 yr.
@article{arxiv.1807.02560,
title = {Resolving the Powerful Radio-loud Quasar at z~6},
author = {E. Momjian and C. Carilli and E. Banados and F. Walter and B. Venemans},
journal= {arXiv preprint arXiv:1807.02560},
year = {2018}
}