Optical spectroscopy of SDSS J004054.65-0915268: three possible scenarios for the classification. A z \sim 5 BL Lacertae, blue FSRQ or a weak emission line quasar

M. Landoni, A. Zanutta, A. Bianco +3

The haunt of high redshift BL Lacerate objects is day by day more compelling, to firmly understand their intrinsic nature and evolution. SDSS J004054.65-0915268 is, at the moment,…