PSO J0309+27 is the most distant blazar known to date, with a redshift of 6.1. It was discovered by cross-matching the NVSS radio catalog with the optical Pan-STARRS survey by using the drop-out method. A Large Binocular Telescope spectroscopic observation confirmed the high-z nature of the source. After its discovery a multi-wavelength study of PSOJ0309+27 has been started (and it is on-going), thanks to several ground based telescopes and satellites, to better understand its properties in different bands (such as radio power, X-ray emission, mass of the central supermassive black hole). In this seminar I will summarize what we know to date of this powerful and unique high-z radio quasar, what type of studies have been done to date, what type of results have been found, and the future prospective.
A detailed overview of PSOJ0309+27, a blazar at z>6