Multi-frequency quasi-simultaneous observations of six very low synchrotron peaked blazars

TL;DR

This study used multi-frequency quasi-simultaneous observations to estimate the synchrotron peak frequencies of six VLSP blazars, confirming the classification for two and revising it for four others.

Contribution

First estimation of synchrotron peak frequencies for six VLSP blazars using quasi-simultaneous spectral data, refining their classification.

Findings

Confirmed VLSP classification for two blazars.

Reclassified four blazars with higher peak frequencies.

Abstract

We have made an estimation of the synchrotron peak frequency ($\nu_{peak}^{s}$) for six very low synchrotron peaked (VLSP) blazars. These objects were selected as VLSP candidates (with the $\nu_{peak}^{s} \leq 10^{13}$ Hz) from the archival data. We have build spectral energy distribution using quasi-simultaneous observations at the Zeiss-1000 and RATAN-600 telescopes of the Special astrophysical observatory of RAS and made an estimation of the $\nu_{peak}^{s}$. We confirmed classification as a VLSP for two sources ([HB89] 1308+326 and 3C 345), for four other blazars we have calculated $\nu_{peak}^{s}>10^{13}$ Hz.