Speaker
Luca Ighina
(Dipartimento di Fisica Giuseppe Occhialini. Università degli Studi Milano Bicocca, Piazza dell'Ateneo Nuovo, 1, 20126 Milano, Italy)
Description
We present the X-ray properties of a complete and well-defined sample of 24 high-z (z=4-5.5) blazar candidates selected from the CLASS radio survey. After completing the existing archival data (Swift-XRT, Chandra and XMM-Newton) with dedicated Swift-XRT observations, we identified the bona-fide blazars based on the X-ray intensity (compared to the optical one) and flatness of the spectrum. We then compared their X-ray-to-radio luminosity ratios with a sample of confirmed blazars at lower redshifts ($\bar{𝑧}$=1.1), finding a significant difference in the two populations. We interpret this redshift-dependant evolution as due to the interaction of the electrons within an extended part of the jet with the Cosmic Microwave Background photons.
| Affiliation | Università degli Studi Milano-Bicocca |
|---|---|
| Topic | Active Galactic Nuclei: accretion physics and evolution across cosmic time |
Primary author
Luca Ighina
(Dipartimento di Fisica Giuseppe Occhialini. Università degli Studi Milano Bicocca, Piazza dell'Ateneo Nuovo, 1, 20126 Milano, Italy)
Co-authors
Alessandro Caccianiga
(Istituto Nazionale di Astrofisica (INAF))
Alberto Moretti
(Istituto Nazionale di Astrofisica (INAF))
Silvia Belladitta
(Istituto Nazionale di Astrofisica (INAF))
Roberto Della Ceca
(Istituto Nazionale di Astrofisica (INAF))
Lucia Ballo
Daniele Dallacasa
(Istituto Nazionale di Astrofisica (INAF))
