Astrophysique à Haute Energie

One of the main current efforts in high-energy astrophysics and astroparticle physics is the development of multi-messenger astronomy, aiming at studying the universe and exploring fundamental physics through four complementary channels: photons, neutrinos, gravitational waves and cosmic rays.

Vue d’artiste du pulsar de Vela, au centre, et sa magnétosphère, dont la périphérie est marquée par le cercle brillant. Les traces bleues émergeant vers l’extérieur illustrent les trajectoires des particules accélérées. Celles-ci produisent le rayonnement gamma le long des bras d’une spirale tournante, par collisions avec des photons infrarouges émis dans la magnétosphère (en rouge). © Science Communication Lab for DESY

Increasing the number of sensitive pixels in an instrument is a classical way to improve its observational capabilities. From cosmology, in the millimeter wave range, to high-energy astrophysics space instruments, the readout of thousands of cryogenic detectors requires dedicated electronic developments. Application-specific integrated circuits - ASICs offer major advantages in this context : specific design, small size and optimized performances.
Les systèmes binaires X sont des systèmes composés d'un objet compact (un trou noir ou bien une étoile à neutrons) et d'une étoile. Ces systèmes sont "transitoires", c'est-à-dire qu'ils passent la majeure partie de leur temps dans un état dit de "quiescence" où ils sont au repos et très peu brillants.
Recently completed, the Large High Altitude Air Shower Observatory (LHAASO) is the most sensitive detector exploring the sky in the ultra-high-energy (UHE, > 0.1 PeV) gamma-ray domain. It already detected about a dozen sources, whose spectra extend up to photon energies exceeding 1 PeV. Such photons are produced in interactions between protons of multi-PeV energy with ambient matter. These observations are extremely important because, in order to explain the observed spectrum of Galactic cosmic rays, astrophysical sources capable of accelerating protons beyond 1 PeV must exist.
Recently completed, the Large High Altitude Air Shower Observatory (LHAASO) is the most sensitive detector exploring the sky in the ultra-high-energy (UHE, > 0.1 PeV) gamma-ray domain. It already detected about a dozen sources, whose spectra extend up to photon energies exceeding 1 PeV. Such photons are produced in interactions between protons of multi-PeV energy with ambient matter. These observations are extremely important because, in order to explain the observed spectrum of Galactic cosmic rays, astrophysical sources capable of accelerating protons beyond 1 PeV must exist.