Description
Optically luminous quasars at z>5 are important probes of super-massive black hole (SMBH) formation. With new and future radio facilities, the discovery of the brightest low-frequency radio sources in this epoch would be an important new probe of cosmic reionization through 21-cm absorption experiments. We present the result of a study of the low-frequency radio properties of a sample of 115 known spectroscopically confirmed z>5 quasars using the second data release of the Low Frequency Array (LOFAR) Two Meter Sky survey (LoTSS-DR2), reaching noise levels of 80uJy/beam (at 144MHz) over an area of 5720 square degrees. We find that 41 sources (36%) are detected in LoTSS-DR2 at >2{sigma} significance and we explore the evolution of their radio properties (power, spectral index, and radio loudness) as a function of redshift and rest-frame ultra-violet properties.
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