Flux-density measurements of the high-redshift blazar PSO J047.4478+27.2992 at 4.7 and 8.2 GHz with RATAN-600

We report the first detection at 4.7 and 8.2 GHz with the RATAN-600 radio telescope of the source PSO J047.4478+27.2992, which has been announced as a blazar at z = 6.1. The average flux densities are 12 +/- 3 and 8 +/- 4 mJy at 4.7 and 8.2 GHz respectively, and an upper limit is estimated as 3 mJy at 11.2 GHz. The light curve at 4.7 GHz, obtained on a time-scale of four months, exhibits moderate variability of the source (fractional variability F-var = 0.28 +/- 0.02). The new RATAN-600 measurements extend previous literature data to higher frequencies, indicating a single power-law radio spectrum with alpha(0.147-8.2) = -0.51 +/- 0.1. The monochromatic radio luminosity at 4.7 GHz P-nu similar to 2 x 10(27) W Hz(-1) is consistent with values for high-redshift quasars at z >= 3.

Automated summary

This paper reports the first detection of the source PSO J047.4478+27.2992, identified as a blazar at z=6.1, using the RATAN-600 radio telescope at 4.7 and 8.2 GHz. The source shows moderate variability and a single power-law radio spectrum, consistent with high-redshift quasars.