Context. Blazars are variable sources on various timescales over a broad energy range spanning from radio to very high energy (>100 GeV, hereafter VHE). Mrk 501...

We present the results of an intensive ultraviolet monitoring campaign on the Seyfert I galaxy NGC 4151, as part of an effort to study its short-timescale...

This paper combines data from the three preceding papers in order to analyze the multi-wave-band variability and spectral energy distribution of the Seyfert I...

We characterized the broad-band X-ray spectra of Swift J1745-26 during the decay of the 2013 outburst using INTEGRAL ISGRI, JEM-X and Swift XRT. The X-ray...

Galactic black hole transients show many interesting phenomena during outburst decays. We present simultaneous X-ray (RXTE, Swift, and INTEGRAL), and optical...

The BL Lac object 1ES 1011+496 was discovered at very high energy (VHE, E > 100GeV) γ-rays by Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) in Spring...

We report on a long-lasting, elevated gamma-ray flux state from VER J0521+211 observed by VERITAS, MAGIC, and Fermi-LAT in 2013 and 2014. The peak integral flux...

We present observations from X-ray to mid-infrared wavelengths of the most energetic non-quasar transient ever observed, AT2021lwx. Our data show a single...

A detailed multiwavelength study of the properties of the triple-peaked active galactic nucleus (AGN) Mrk 622 showing different aspects of the nuclear emission...