X-ray emission from hot bubbles in Nebulae around Evolved Stars

I present the observational and numerical results of my phd thesis
developed in the past three years. These results account for
high-quality X-ray observations of diffuse X-ray emission in Wolf-Rayet
nebulae and planetary nebulae (PNe) in comparison with optical and infrared
observations. Our numerical simulations were tailored to study the formation,
evolution, and X-ray emission from PNe. These results help us study the
role of instabilities in the creation of clumps and filaments to reduce the 
temperature of the hot bubble to observable values.