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Identifying the Composition of Supernova Remnants

The remnants from the supernova explosions of massive stars are the birth place for many of the chemical elements. These elements come from the star itself, from elements created in the explosion of the star, and from gas around the star that exploded. Astro-E2, with its ability to determine the energy of X-rays very precisely, will help us learn more about the elements in supernova remnants.

During a supernova explosion, a massive star ejects gas out into space. The force of the explosion also sends a shock wave into space. As this shock wave interacts with the ejected gas, the gas heats up and emits x-rays. Because the gas is hot, some of the electrons are stripped from the atoms in the gas, and the atoms becomes ionized. The energies of the electrons remaining in the atom are raised, and then decay again, emitting light at specific energies. By observing these emission lines we can identify the element, the degree of ionization of the atoms, and how much of the particular element is in the gas. Some of the elements we see are those created by the energy of the supernova explosion. With its sensitivity, Astro-E2 will also be able to identify and measure less abundant elements in SNR, such as sodium, aluminum, cobalt, and nickel.

As the shock wave continues to expand, it also heats up the gas that surrounded the star. In some remnants it is difficult to distinguish whether a particular element is coming from the ejected material or was already present in the surrounding gas. Astro-E2 will help to unravel these puzzles.

The x-ray spectrum from a supernova remnant, showing the emission lines from different elements

Imagine the Universe is a service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Nicholas White (Director), within the Exploration of the Universe Division (EUD) at NASA's Goddard Space Flight Center.

The Imagine Team
Project Leader: Dr. Jim Lochner
Curator:Meredith Bene
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