• DOI:10.3847/1538-4357/abe710
• Corpus ID: 232148026

Enhanced X-Ray Emission from the Most Radio-powerful Quasar in the Universe’s First Billion Years

@article{Connor2021EnhancedXE,
  title={Enhanced X-Ray Emission from the Most Radio-powerful Quasar in the Universe’s First Billion Years},
  author={Thomas Connor and Eduardo Ba{\~n}ados and Daniel Stern and Christopher L. Carilli and Andrew C. Fabian and Emmanuel Momjian and Sof{\'i}a Rojas-Ruiz and Roberto Decarli and Emanuele Paolo Farina and Chiara Mazzucchelli and Hannah P. Earnshaw},
  journal={The Astrophysical Journal},
  year={2021},
  volume={911}
}

• T. Connor, E. Bañados, +8 authors H. Earnshaw
• Published 5 March 2021
• Physics
• The Astrophysical Journal

We present deep (265 ks) Chandra X-ray observations of PSO J352.4034−15.3373, a quasar at z = 5.831 that, with a radio-to-optical flux ratio of R > 1000, is one of the radio-loudest quasars in the early universe and is the only quasar with observed extended radio jets of kiloparsec scale at z ≳ 6. Modeling the X-ray spectrum of the quasar with a power law, we find a best fit of Γ=1.99−0.28+0.29 , leading to an X-ray luminosity of L2–10=1.26−0.33+0.45×1045ergs−1 and an X-ray to UV brightness ratio of α OX = −1.45 ± −0.11. We identify a diffuse structure 50 kpc (∼8″) to the NW of the quasar along the jet axis that corresponds to a 3σ enhancement in the angular density of emission and can be ruled out as a background fluctuation with a probability of P = 0.9985. While with few detected photons the spectral fit of the structure is uncertain, we find that it has a luminosity of L 2–10 ∼ 1044 erg s−1. These observations therefore potentially represent the most distant quasar jet yet seen in X-rays. We find no evidence for excess X-ray emission where the previously reported radio jets are seen (which have an overall linear extent of 0.″28), and a bright X-ray point source located along the jet axis to the SE is revealed by optical and NIR imaging to not be associated with the quasar.