6 papers
Exploring the nature of Galactic unassociated sources detected by the Fermi-LAT
F. Acero, A. Acharyya, A. Adelfio +120
We investigate the nature of the unassociated sources detected by the Fermi-LAT close (|b|<10°) to the Galactic plane, representing 16% of all sources in the 4FGL-DR4 catalog. The…
Tracking down the broadband polarimetric properties of PG 1553+113
Riccardo Middei, Svetlana G. Jorstad, Alan P. Marscher +78
We report on a nine-month monitoring campaign of the blazar PG 1553+113, relying on three observations carried out in 2025 with the Imaging X-ray Polarimetry Explorer (IXPE) and su…
Probing the statistical correlation of optical tidal disruption events with high-energy neutrinos
D. A. Langis, I. Liodakis, K. I. I. Koljonen +1
High-energy (HE) neutrinos have been observed by the IceCube (IC) Neutrino observatory for over a decade. Nevertheless, the astrophysical origin and the responsible mechanisms prod…
Repeating flares, X-ray outbursts and delayed infrared emission: A comprehensive compilation of optical tidal disruption events
D. A. Langis, I. Liodakis, K. I. I. Koljonen +10
TDEs have been proposed as valuable laboratories for studying dormant black holes. However, progress in this field has been hampered by the limited number of observed events. In th…
Intra-night optical polarization monitoring of blazars
Aristeidis Polychronakis, Ioannis Liodakis, Anastasia Glykopoulou +20
Blazars are known for their extreme variability across the electromagnetic spectrum. Variability at very short timescales can push the boundaries between competing models offering…
X-ray reverberation modelling of the continuum, optical/UV time-lags in quasars
D. A. Langis, I. E. Papadakis, E. Kammoun +2
Context: Extensive, multi-wavelength monitoring campaigns of nearby and higher redshift active galactic nuclei (AGN) have shown that the UV/optical variations are well correlated w…