Is the X-ray bright z=5.5 quasar SRGE J170245.3+130104 a blazar?
Monthly Notices of the Royal Astronomical Society(2023)
Abstract
Jets may have contributed to promoting the growth of seed black holes in the early Universe, and thus observations of radio-loud high-redshift quasars are crucial to understanding the growth and evolution of the early supermassive black holes. Here we report the radio properties of an X-ray bright z = 5.5 quasar, SRGE J170245.3 + 130104 (J1702 + 1301). Our high-resolution radio images reveal the radio counterpart at the optical position of J1702 + 1301, while another radio component is also detected at similar to 23.5 arcsec to the south-west. Our analysis suggests that this south-west component is associated with a foreground galaxy at z asymptotic to 0.677, which is mixed with J1702 + 1301 in low-frequency low-resolution radio images. After removing the contamination from this foreground source, we recalculated the radio loudness of J1702 + 1301 to be R > 1100, consistent with those of blazars. J1702 + 1301 exhibits a flat radio spectrum ( alpha = -0.17 +/- 0.05, S proportional to nu(alpha)) between 0.15 and 5 GHz; abo v e 5 GHz, it shows a rising spectrum shape, and the spectral index alpha(8 . 2)(4 . 7) appears to be correlated with the variation of the flux density: in burst states, alpha(8 . 2)(4 . 7) becomes larger. J1702 + 1301 displays distinct radio variability on time-scales from weeks to years in the source's rest frame. These radio properties, including high radio loudness, rising spectrum, and rapid variability, tend to support it as a blazar.
MoreTranslated text
Key words
galaxies: active,galaxies: high-redshift,galaxies: jets,quasars: individual: SRGE J170245.3+130104
AI Read Science
Must-Reading Tree
Example
![](https://originalfileserver.aminer.cn/sys/aminer/pubs/mrt_preview.jpeg)
Generate MRT to find the research sequence of this paper
Chat Paper
Summary is being generated by the instructions you defined