Résumé
The new infrared integral field spectrometer on the VLT, SINFONI, has allowed several breakthroughs in Galactic Centre research, e.g. concerning the dynamics and origin of massive stars orbiting the supermassive black hole candidate SgrA* and the determination of the spectral energy distribution of its energetic outbursts (flares). We want to thank Pierre Léna for his early involvement in the instrumental project that is the natural follow-up to SINFONI and will undoubtedly bring the next lot of breakthroughs: GRAVITY. With an imaging resolution of a few milliarcseconds and an astometric accuracy of ≃ 10 pas, this second generation instrument for the VLT Interferometer will be able to measure the proper motion of matter (stars or hot spots in the accretion disk) down to the event horizon of the black hole, hereby probing spacetime in its immediate vicinity.
Après les avancées considérables apportées par le spectro-imageur SINFONI, nous sommes en train de concevoir GRAVITY, un instrument de seconde génération pour le VLTI qui nous permettra de sonder l'espace-temps à proximité immédiate de l'horizon d'un trou noir.