TY - JOUR
T1 - The Discovery of a Highly Accreting, Radio-loud Quasar at z = 6.82
AU - Bantados, Eduardo
AU - Mazzucchelli, Chiara
AU - Momjian, Emmanuel
AU - Eilers, Anna Christina
AU - Wang, Feige
AU - Schindler, Jan Torge
AU - Connor, Thomas
AU - Andika, Irham Taufik
AU - Barth, Aaron J.
AU - Carilli, Chris
AU - Davies, Frederick B.
AU - Decarli, Roberto
AU - Fan, Xiaohui
AU - Farina, Emanuele Paolo
AU - Hennawi, Joseph F.
AU - Pensabene, Antonio
AU - Stern, Daniel
AU - Venemans, Bram P.
AU - Wenzl, Lukas
AU - Yang, Jinyi
N1 - Publisher Copyright:
© 2021. The Author(s). Published by the American Astronomical Society..
PY - 2021/3/1
Y1 - 2021/3/1
N2 - Radio sources at the highest redshifts can provide unique information on the first massive galaxies and black holes, the densest primordial environments, and the epoch of reionization. The number of astronomical objects identified at z > 6 has increased dramatically over the last few years, but previously only three radio-loud (R 2500 = f ν,5 GHz/f ν,2500 Å > 10) sources had been reported at z > 6, with the most distant being a quasar at z = 6.18. Here we present the discovery and characterization of PSO J172.3556+18.7734, a radio-loud quasar at z = 6.823. This source has an Mg ii-based black hole mass of ∼3 × 108 M o˙ and is one of the fastest accreting quasars, consistent with super-Eddington accretion. The ionized region around the quasar is among the largest measured at these redshifts, implying an active phase longer than the average lifetime of the z ⪆ 6 quasar population. From archival data, there is evidence that its 1.4 GHz emission has decreased by a factor of two over the last two decades. The quasar's radio spectrum between 1.4 and 3.0 GHz is steep (α = -1.31). Assuming the measured radio slope and extrapolating to rest-frame 5 GHz, the quasar has a radio-loudness parameter R 2500 ∼ 90. A second steep radio source (α = -0.83) of comparable brightness to the quasar is only 23.″1 away (∼120 kpc at z = 6.82; projection probability <2%), but shows no optical or near-infrared counterpart. Further follow-up is required to establish whether these two sources are physically associated.
AB - Radio sources at the highest redshifts can provide unique information on the first massive galaxies and black holes, the densest primordial environments, and the epoch of reionization. The number of astronomical objects identified at z > 6 has increased dramatically over the last few years, but previously only three radio-loud (R 2500 = f ν,5 GHz/f ν,2500 Å > 10) sources had been reported at z > 6, with the most distant being a quasar at z = 6.18. Here we present the discovery and characterization of PSO J172.3556+18.7734, a radio-loud quasar at z = 6.823. This source has an Mg ii-based black hole mass of ∼3 × 108 M o˙ and is one of the fastest accreting quasars, consistent with super-Eddington accretion. The ionized region around the quasar is among the largest measured at these redshifts, implying an active phase longer than the average lifetime of the z ⪆ 6 quasar population. From archival data, there is evidence that its 1.4 GHz emission has decreased by a factor of two over the last two decades. The quasar's radio spectrum between 1.4 and 3.0 GHz is steep (α = -1.31). Assuming the measured radio slope and extrapolating to rest-frame 5 GHz, the quasar has a radio-loudness parameter R 2500 ∼ 90. A second steep radio source (α = -0.83) of comparable brightness to the quasar is only 23.″1 away (∼120 kpc at z = 6.82; projection probability <2%), but shows no optical or near-infrared counterpart. Further follow-up is required to establish whether these two sources are physically associated.
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U2 - 10.3847/1538-4357/abe239
DO - 10.3847/1538-4357/abe239
M3 - Article
AN - SCOPUS:85103163979
SN - 0004-637X
VL - 909
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 80
ER -