Multi-wavelength picture of the misaligned BL Lac object 3C 371

TL;DR

This study provides a comprehensive multiwavelength analysis of the blazar 3C 371, combining optical, radio, X-ray, and gamma-ray data to understand its variability, jet kinematics, and spectral energy distribution over several years.

Contribution

It offers a detailed long-term multiwavelength variability study of 3C 371, including jet kinematics and SED modeling, which advances understanding of misaligned BL Lac objects.

Findings

Detected correlated variability across multiple bands.

Identified jet components and their propagation speeds.

Modeled the broadband SED with theoretical emission scenarios.

Abstract

The BL Lac object 3C 371 is one of the targets that are regularly monitored by the Whole Earth Blazar Telescope (WEBT) Collaboration to study blazar variability on both short and long timescales. We aim to evaluate the long-term multiwavelength (MWL) behaviour of 3C 371, comparing it with the results derived for its optical emission in our previous study. For this, we make use of the multi-band campaigns organized by the WEBT Collaboration in optical and radio between January 2018 and December 2020, and of public data from Swift and Fermi satellites and the MOJAVE Very Large Interferometry programme. We evaluate the variability shown by the source in each band with the amplitude variability quantification, as well as possible interband correlation using the z-Discrete Correlation Function. We also present a deep analysis of the optical-UV, X-ray and $\gamma$-ray spectral variability. With the MOJAVE data we perform a kinematics analysis, looking for components propagating along the jet, calculating its kinematics parameters. This set of parameters is later used for the interpretation of the source MWL behaviour, modelling the broadband spectral energy distribution (SED) of the source with theoretical blazar emission scenarios.