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

Monthly Notices of the Royal Astronomical Society, Volume 503, Issue 3, pp.4662-4666

Mufakharov T., Mikhailov A., Sotnikova,Yu, Mingaliev M., Stolyarov V., Erkenov A., Nizhelskij N., Tsybulev P.

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 α_0.147-8.2 = -0.51 ± 0.1. The monochromatic radio luminosity at 4.7 GHz Pν ∼ 2 × 10^27 W Hz^-1 is consistent with values for high-redshift quasars at z ≥ 3. Original →