École Nationale Supérieure de
Techniques Avancées

Abstract

During my internship, I was able to understand the cataclysmic variables and more particularly, the physics of the accretion shock. The latter is responsible for the observed radiative phenomena from the Earth. From these observations, we can deduce some of the characteristics of a magnetic cataclysmic variable, such as the mass, the intensity of the magnetic field and the rotation period of the white dwarf, but also the accretion rate and the orbital period of the system. We also observe oscillations of the light curve in the optical domain. To understand this phenomenon, I studied the cooling within the accretion column and in particular the cooling by bremsstrahlung radiation. This led me to perform simulations on the astrophysical scale to highlight the cooling and Falle instabilities within the accretion column. These are responsible for the oscillations of the shock front. Finally, I set up simulations at the laboratory scale. I studied the physics of accretion column experiments in the laboratory with the ultimate goal of reproducing the oscillations observed at the astrophysical scale during a laboratory experiment on the Megajoule laser.