Exploring the Radio Spectral Energy Distribution of the Ultraluminous Radio-quiet Quasar SDSS J0100+2802 at Redshift 6.3

Release time:2023-03-22 Hits:

Impact Factor:5.8

DOI number:10.3847/1538-4357/ac5c50

Journal:The Astrophysical Journal

Abstract:We report deep Karl G. Jansky Very Large Array (VLA) observations of the optically ultraluminous and radio-quiet quasar SDSS J010013.02+280225.8 (hereafter J0100+2802) at redshift z = 6.3. We detected the radio continuum emission at 1.5 GHz, 6 GHz, and 10 GHz. This leads to a radio power-law spectral index of α = −0.52 ± 0.18 (S ∝ να). The radio source is unresolved in all VLA bands with an upper limit to the size of 0farcs2 (i.e., ∼1.1 kpc) at 10 GHz. We find variability in the flux density (increase by ∼33%) and the spectral index (steepened) between observations in 2016 and 2017. We also find that the VLA 1.5 GHz flux density observed in the same year is 1.5 times that detected with the Very Long Baseline Array (VLBA) in 2016 at the same frequency. This difference suggests that half of the radio emission from J0100+2802 comes from a compact core within 40 pc, and the rest comes from the surrounding few-kiloparsec area, which is diffuse and resolved out in the VLBA observations. The diffuse emission is 4 times brighter than what would be expected if driven by star formation. We conclude that the central active galactic nucleus is the dominant power engine of the radio emission in J0100+2802.

Co-author:Ran Wang, Emmanuel Momjian, Jeff Wagg, Xiaolong Yang, Tao An, Yali Shao, Chris L. Carilli, Xue-Bing Wu, Xiaohui Fan, Fabian Walter, Linhua Jiang, Qiong Li1,2, Jianan Li, Qinyue Fei, and Fuxiang Xu

First Author:Yuanqi Liu

Volume:929

Issue:1

Page Number:69

Translation or Not:no

Date of Publication:2022-04-13

Included Journals:SCI

Links to published journals:https://iopscience.iop.org/article/10.3847/1538-4357/ac5c50