Compact objects, black holes and pulsars, cosmic radiation and particle acceleration

We study a wide range of high-energy astrophysics at IRAP.

On the one hand, we study the nature and physics of the most compact and energetic objects in the universe. We identify and characterize these objects as completely as possible – black holes, neutron stars, magnestars, pulsars – with regular discoveries such as intermediate-sized black holes or ultra-light sources. We establish constraints on the state of the constituent matter of these objects. We study their interactions with the environment, the different accretion and ejection regimes, tidal forces and stellar erosion, the formation of disks and jets, the acceleration and the resulting radiation. We also model the very energetic plasmas that characterize these environments, including the physics of shocks, nucleosynthesis, the various processes of radiation, dynamics (hydro and magnetohydrodynamics), transport and propagation of very high energy particles.

On the other hand, we study the phenomena of particle acceleration in the Universe, their impact on the environment and on the galactic and cosmological explosive phenomena that underlie their origin. Novae, supernovae and gamma-ray bursts, their interstellar remnants and diffuse emissions resulting from the interactions of particles with the interstellar medium are at the center of our studies: for example, gamma-ray radiation from explosions of novae, supernovae, and gamma-ray bursts. The interaction of the shock waves produced during these explosions with the interstellar medium is a favorable site for the acceleration of particles that we study at high energy. This emission informs us about the propagation of particles in the interstellar medium, and allows us to study their impact on their environment. We combine analytical and numerical modeling work (shocks, kinetic transport and acceleration processes), as well as instrumental developments and observations, in particular Fermi, INTEGRAL, Swift, TAROT and XMM-Newton. We are also involved in future projects such as SKA, Athena, and in particular CTA and SVOM currently in development at IRAP.

A major evolution of our fields is ‘multi-messenger’ astrophysics and the connection with the detection of gravitational waves (LIGO/VIRGO). In these fields, our main instruments are INTEGRAL, XMM-Newton, Chandra, NuSTAR, Swift, FERMI, with a view to SVOM, CTA, ATHENA, LISA.