CEA's teams are deeply involved in major European and international programmes for which research instruments (from earth-based observatories to space telescopes) are built and used. They helped advance our understanding of the Universe.
DEFINITION
WHAT IS THE UNIVERSE?
VIEWPOINT
THE UNIVERSE HAS MORE IMAGINATION THAN MANKIND DOES
By Catherine Cesarsky, astrophysicist and member of the French Académie des sciences
CONTEXT
ASTROPHYSICS, A CHALLENGING TECHNOLOGICAL QUEST
I DYNAMICS OF STARS AND EXOPLANETS
The Sun and its surrounding planets are no longer alone in the Universe. We know that exoplanets orbit around the vast majority of the multitude of identified stars. We thus see a convergence of interest between solar and stellar research and exoplanet research: a clear understanding of the host star enables us to better understand its planet(s) and the resulting space and habitability conditions.
- SOLAR AND STELLAR DYNAMICS
- EXOPLANETS
- STAR-PLANET INTERACTIONS
II STAR FORMATION AND INTERSTELLAR MEDIUM
Stars power the main engine in the evolution of our astronomical environment, feeding the cycle of matter and energy in the galaxies. We are also closely tied to them because they are the source of the main chemical elements of which we are made. Their birth, or rather their formation, is complex and takes place in the densest clouds of gas and dust in the galaxies. By probing these dense clouds, new links between the mechanisms which regulate the star formation and those which structure the interstellar medium on large scales have been discovered, as well as the quasi systematic presence of matter in disks around protostars. The exoplanets, which we now catalogue by the thousands form in such disks.
- THE INTERSTELLAR ECOSYSTEM
- ALONG INTERSTELLAR FILAMENTS
- AT THE HEART OF PROTOPLANETARY DISKS
III COSMOLOGY AND EVOLUTION OF GALAXIES
From the scales of galaxies, to galaxy clusters, to the very Large structures of the Universe, cosmology aims to produce a scenario able to go back to the origins of the forms in the Universe and to use the Universe as a laboratory in which to test the fundamental laws of physics and the existence of components as yet undetectable in the laboratory, such as dark matter and energy.
- THE COSMOLOGICAL IMPLICATIONS OF THE LARGE GALACTIC SURVEYS
- THE ORIGIN OF COSMIC ACCELERATION: NEW ENERGY OR NEW PHYSICS?
- GALAXY CLUSTERS AS PHYSICS LABORATORIES
- LARGE SURVEYS OF GALAXY CLUSTERS AND COSMOLOGY
- OBSERVING THE FORMATION AND EVOLUTION OF THE FIRST GENERATION OF GALAXY CLUSTERS
- THE ENIGMATIC FORMATION OF MASSIVE GALAXIES
IV HIGH-ENERGY PHENOMENA
High-energy astrophysics is the study of the most violent phenomena in our Universe: explosions of massive stars and the formation of compact stars (pulsars, magnetars, black holes), shocks and acceleration of cosmic rays, accretion and relativistic ejections by compact stars. These objects are laboratories for the physics of the extreme: the compactness, magnetic and gravitational fields, shocks, acceleration and speed involved are the most intense permitted by contemporary physics. These phenomena are being studied at CEA using theoretical, numerical and experimental approaches.
- SUPERNOVA: UNDERSTANDING THE EXPLOSION OF MASSIVE STARS
- EXTREME EXPLOSIONS
- SUPERNOVA REMNANTS AND COSMIC RADIATION: THE GAMMA SKY SHEDS LIGHT ON THE MATTER
- RELATIVISTIC JET EJECTIONS IN MICROQUASARS
OUTLOOK
TOWARDS NEW DISCOVERIES!