Padovani, P.P.PadovaniGiommi, PaoloPaoloGiommiRau, A.A.Rau2020-09-172020-09-172012-05-01https://hdl.handle.net/20.500.13025/2917Monthly Notices of the Royal Astronomical Society Letters, Volume 422, Issue 1, pp. 48-52.We study the quasi-simultaneous near-IR, optical, ultraviolet and X-ray photometry of 11 γ-ray selected blazars for which redshift estimates larger than 1.2 have been recently provided. Four of these objects turn out to be high-power blazars with the peak of their synchrotron emission between ∼3 × 10^15 and ∼10^16 Hz, and therefore of a kind predicted to exist but never seen before. This discovery has important implications for our understanding of physical processes in blazars, including the so-called ‘blazar sequence’, and might also help in constraining the extragalactic background light through γ-ray absorption since two sources are strongly detected even in the 10–100 GeV Fermi-LAT band. Based on our previous work and their high powers, these sources are very likely high-redshift flat-spectrum radio quasars, with their emission lines swamped by the non-thermal continuum.enradiation mechanisms: non-thermalBL Lacertae objects: generalradio continuum: galaxiesgamma-rays: galaxiesX-rays: galaxiesjournal article10.1111/j.1745-3933.2012.01234.xhttps://academic.oup.com/mnrasl/article/422/1/L48/971147?login=true2012MNRAS.422L..48P