Related papers: H.E.S.S. observations following multi-messenger al…
The LIGO-Virgo-KAGRA (LVK) collaboration has recently made it possible for early warning alerts to be sent out, potentially before the end of the gravitational wave (GW) emission from a neutron star binary. If we get such alerts in this…
The IceCube Neutrino Observatory is active in multi-messenger follow-ups of Gravitational Wave (GW) events. Since the release of the Gravitational Wave Transient Catalogue (GWTC)-2.1 by the LIGO-Virgo-KAGRA (LVK) collaboration,…
Following the detection of high-energy astrophysical neutrinos in 2013, their origin is still unknown. Aiming for the identification of an electromagnetic counterpart of a rapidly fading source, we have implemented a realtime analysis…
A 3-day international workshop on atmospheric monitoring and calibration for high-energy astroparticle detectors, with a view towards next-generation facilities. The atmosphere is an integral component of many high-energy astroparticle…
A detailed multi-messenger study of the high-energy emission from the Galactic plane is possible nowadays thanks to the observations provided by gamma and neutrino telescopes and could be mandatory in order to obtain a consistent scenario.…
Weakly interacting neutrinos are ideal astronomical messengers because they travel through space without deflection by magnetic fields and, essentially, without absorption. Their weak interaction also makes them notoriously difficult to…
The Radio Neutrino Observatory in Greenland (RNO-G) is the only ultrahigh energy (UHE, ${\gtrsim}30$~PeV) neutrino monitor of the Northern sky and will soon be the world's most sensitive high-uptime detector of UHE neutrinos. Because of…
The ANTARES neutrino telescope detects the Cherenkov radiation emitted along the path of charged particles produced in neutrino interactions. ANTARES is sensitive to all flavors even though it is optimized for muon neutrinos. Several…
The Cherenkov Telescope Array (CTA) is a next generation ground-based very-high-energy gamma-ray observatory that will allow for observations in the >10 GeV range with unprecedented photon statistics and sensitivity. This will enable the…
With the installation of a new 28-m diameter imaging atmospheric Cherenkov telescope in the middle of the array, the H.E.S.S. instrument has entered since 2012 into its Phase II. The fifth large-size telescope is particularly important to…
This review provides an overview of recent advances in multi-wavelength and multi-messenger observations of blazars, the current status of theoretical models for blazar emission, and prospects for future facilities. The discussion of…
This thesis presents the study of four aspects of high energy astronomy. The first part of the thesis is dedicated to an aspect of instrument development for imaging atmospheric Cherenkov telescopes, namely the Level 2 trigger system of the…
Neutrino telescopes, including IceCube, can detect galactic supernova events by observing the collective rise in photomultiplier count rates with a sub-second time resolution. Leveraging precise timing, we demonstrate the ability of…
The presence of substructures in dark matter haloes is an unavoidable consequence of the cold dark matter paradigm. Indirect signals from these objects have been extensively searched for with cosmic rays and gamma-rays. At first sight,…
The High Energy Stereoscopic System (H.E.S.S.) experiment, a ground-based gamma-ray Cherenkov telescope array located in Namibia, has now detected many extragalactic objects, which redshifts range from z=0.00183 up to z=0.2, possibly more.…
Water-(Ice-) Cherenkov neutrino telescopes have played a pivotal role in the search and discovery of high-energy astrophysical neutrinos. Experimental collaborations are developing and constructing next-generation neutrino telescopes with…
The High-Altitude Water Cherenkov Observatory (HAWC) is a large field of view (~2 sr) continuously operating experiment sensitive to very-high energy (VHE) gamma rays (~0.3-100 TeV). These characteristics make it well suited for observing…
Next-generation gravitational-wave detectors will provide unprecedented sensitivity to inspiraling binary neutron stars and black holes, enabling detections at the peak of star formation and beyond. However, the signals from these systems…
A clue to finding the long-sought sources of cosmic rays is the recent observation of an astrophysical flux of high-energy neutrinos by the IceCube detector, since these possibly originate in hadronic interactions at cosmic-ray…
The ever-increasing sensitivity of the network of gravitational-wave detectors has resulted in the accelerated rate of detections from compact binary coalescence systems in the third observing run of Advanced LIGO and Advanced Virgo. Not…