Science: Supernovae
Mapping young supernovae explosions
Ever since the first few minutes after the Big Bang, when the temperature and density of the Universe fell below that which is required for nuclear fusion, much of the visible content in the Universe has been going through the slow but spectacular lifecycle of matter: star formation and evolution ending in novae or supernovae, with the ejection of heavier elements back into the galaxies to seed a new generation of stars. The unstable balance between gravitational and nuclear forces produces a cycle in which the death of stars leads to the birth of others, maintaining a rich, dynamic story of life, death, and rebirth on the galactic stages of our Universe.
NuSTAR will advance our understanding of this lifecycle through study of supernovae and supernova remnants. Observations of supernovae will probe the physics in the cores of dying stars, and provide unique astrophysical laboratories for studying nuclear physics in extreme conditions only dreamed of in laboratories on Earth. The relics of these explosions, supernova remnants, serve as a primary force in driving the chemical evolution of galaxies through successive generations of stars.
Major advances in our understanding of supernovae will be provided by NuSTAR's ability to study the emission from radioactive nuclei produced in these explosions, fundamental tracers of this cycle of creation. Nuclear decays provide unique signatures of the radioactive isotopes, their quantities, speeds, and depths in their environment. The unstable nuclei provide a direct means of quantifying the underlying processes of nuclear burning in supernovae, novae, and stars. They carry information about the otherwise hidden, extreme conditions under which they were produced. These nuclei allow us to see to the very core of a supernova explosion, revealing critical information about the underlying nuclear ignition, structure, and dynamics of these immensely energetic events.
In addition, supernova remnants shape the evolution of galaxies by plowing through the stellar neighborhoods, sweeping up material into shocks that drive the next generation of star formation. These shocks contain sizable energy, and are believed to power the acceleration of cosmic-ray particles. NuSTAR has unprecedented capabilities to study the hard X-ray emission from supernova remnants, helping reveal the sites and processes of particle acceleration.
Previous X-ray missions began to address this science, but NuSTAR, with its dramatic improvement in sensitivity, imaging resolution, and spectroscopy, provides a powerful new tool for studying the processes occuring in these engines.
