BLAZ4R: the first living catalog of confirmed z>4 blazars
Embedded Files
BLAZ4R is fully described in its first edition in Sbarrato, Belladitta et al. (2026) [LINK], that includes 52 known z>4 blazars, complete with multiwavelength coverage, eROSITA cross-correlation (17 sources with eRASS:5 data), and a focus on their radio features.
Results of the multiwavelength characterisation performed on all sources in BLAZ4R are available in the Catalog page.
Blazars at z>4 are rare but powerful probes of how active supermassive black holes evolve in connection to relativistic jets, in the first 2 billion years of cosmic history.
BLAZ4R includes 52 confirmed blazars, characterized through their X-ray properties, radio spectra and morphology, and multiwavelength profiles.
This catalog keep confirming that jetted sources are significantly more numerous relative to non-jetted counterparts at high-z, and that blazars (and therefore the overall jetted population) do not exhibit significantly different features compared to the total active galactic nuclei population in the early Universe. Fast accretion processes that involve relativistic jets are clearly required to justify the existence of fully formed jetted AGN at z>4. However, the diverse multiwavelength properties characterizing BLAZ4R do not yet allow us to identify the specific signatures of these processes.
We will continue updating BLAZ4R to search for such signatures and ultimately understand the early formation of jetted AGN.
Sky map of BLAZ4R sources and most reliable z>4 blazar candidates.
Comoving number density of active black holes hosted in jetted AGN as traced by blazars, as a function of redshift
Comoving number density of active black holes hosted in jetted AGN as traced by blazars at z>4, as a function of redshift
Reference
Reference
If you make use of the catalogue, please acknowledge by citing Sbarrato, Belladitta et al. [REF] and this website: https://blaz4r.brera.inaf.it/
Page updated
Report abuse