BL Lac objects are active nuclei, hosted in massive elliptical galaxies, the emission of which
is dominated by a relativistic jet closely aligned with the line of sight. This implies the …

The Universe is largely transparent to γ γ-rays in the GeV energy range, making these high-
energy photons valuable for exploring energetic processes in the cosmos. After 7 years of …

We present ten years of R-band monitoring data of 31 northern blazars which were either
detected at very high-energy (VHE) gamma rays or listed as potential VHE gamma-ray …

We report the first> 99% confidence detection of X-ray polarization in BL Lacertae. During a
recent X-ray/γ-ray outburst, a 287 ks observation (2022 November 27–30) was taken using …

The IceCube report of as~ 3.5 excess of 13± 5 neutrino events in the direction of the
blazar TXS 0506+ 056 in 2014–2015 and the 2017 detection of a high-energy neutrino …

The exact location of the γ-ray emitting region in blazars is still controversial. In order to
attack this problem we present first results of a cross-correlation analysis between radio (11 …

Blazars are a class of jet-dominated active galactic nuclei with a typical double-humped
spectral energy distribution. It is of common consensus that the synchrotron emission is …

ABSTRACT Blazar S5 0716+ 714 is well-known for its short-term variability, down to intraday
time-scales. We here present the 2-min cadence optical light curve obtained by the TESS …

Abstract The Vera C. Rubin Legacy Survey of Space and Time (LSST) holds the potential to
revolutionize time domain astrophysics, reaching completely unexplored areas of the …

In an effort to locate the sites of emission at different frequencies and physical processes
causing variability in blazar jets, we have obtained high time-resolution observations of BL …