Longterm optical monitoring of bright BL Lacertae objects with ATOM: Spectral variability and multiwavelength correlations

摘要

Context. Blazars are the established sources of an intense and variable non-thermal radiation extending from radio wavelengths up to high and very high-energy gamma-rays. Understanding the spectral evolution of blazars in selected frequency ranges, as well as multifrequency correlations in various types of blazar sources, is of a primary importance for constraining blazar physics.