We study the quasi-simultaneous near-IR, optical, UV, and X-ray photometry of eleven gamma-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 x 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 constraining the extragalactic background light through gamma-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.
@article{arxiv.1202.2236,
title = {The discovery of high power - high synchrotron peak blazars},
author = {P. Padovani and P. Giommi and A. Rau},
journal= {arXiv preprint arXiv:1202.2236},
year = {2015}
}
Comments
5 pages, 6 colour figures, accepted for publication in the Monthly Notices of the Royal Astronomical Society