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

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 ${\nu }_{peak}^s\le 10^{13}$ 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.

arXiv comment7 pages; published in Astrophysical Bulletin, Volume 70, Issue 3, 2015