Setting the galaxy on fire: supernovae
Setting the galaxy on fire: supernovae
Supernovae explosions mark the end of the life of the heaviest stars inside galaxies. These cosmic fireworks pepper the Universe with heavy elements, critical for life, and play a key role in shaping the evolution of galaxies. Indeed, the energetic explosions of supernovae can blow material out of galaxies in the form of a “galactic wind”. Astrophysicists at the Institute of Computational Cosmology use detailed computer simulations to understand the complex connection between supernovae explosions and the onset of these galactic winds.
By studying how supernovae regulate the gas supply for the formation of new stars, astrophysicists aim to understand the evolution of galaxies throughout the cosmic history.
The movie sequence on the cathedral shows a thin slice through the disk of a galaxy such as the Milky Way (the horizontal band), the horizontal extent is approximately the distance of the Sun to the centre of the Milky Way.
The flashes represent individual supernova explosions that heat the surrounding gas, driving interstellar gas out of the disk in the form of a galactic fountain. These are the waves of hot gas, with a temperature of around 10 million degrees, that you see moving upwards and downwards, at speeds of several 100 kilometres per second. The energy released by a single supernova is equivalent to the total energy emitted by the Sun over its entire lifetime.
The frame rate of the movie is such that 1 second of movie represents 1 million years of elapsed time, which is why you see so many supernovae explode. In the Milky Way, the supernova rate is only one explosion per century, which we know from historical records and from dating supernova remnants.