Chandra Reveals New Details of Star's Afterlife

Astronomers can now better understand how some stars die and how they disperse elements into the next generation of stars and planets. New images from G292.0+1.8 – one of three supernova remnants in the Milky Way that contain large amounts of oxygen at a distance of 20,000 light years – show rapid expansion, intricate structure, debris field that contains (along with oxygen) other elements such as neon and silicon created in the star's core before the explosion.

"We are finding that, just like snowflakes, each supernova remnant is complicated and beautiful in its own way", said Sangwook Park of Penn State who led the work, released in conjunction with the "8 Years of Chandra", symposium in Huntsville, Ala.

Equaling nearly 6 days worth of observing time, the new images show incredible complex structures. G292.0+1.8 is considered a "textbook" case of a supernova created by the death of a massive star, X-ray images showing the exact chemical elements distribution ejected in the supernova. After a complete study of the images from Chandra X-ray Telescope, it was noticed that the supernova explosion was asymmetrical, different chemical elements being unevenly spread. These elements light up at different temperatures, indicating that the temperature is higher in the upper right portion of G292.0+1.8.

A remnant of the original star can also be seen to the left of the center of G292.0+1.8 – it’s a dense, rapid-rotation neutron star also known as a pulsar, moved from its original position (in the center of the supernova) by explosion to its present position.

Surrounding the pulsar is a so-called pulsar wind nebula, a magnetized bubble of high-energy particles, a structure easily seen in X-rays. The spin direction and the kick direction don’t seem to be aligned, in contrast to apparent spin-kick alignments in some other supernova remnants.

An intriguing feature is the fact the parent star and the remnant pulsar seem to share the same spin-axis, easily seen by comparing the equatorial belt produced before the explosion by expelled material around its equator via winds, and the current spin-axis of the remaining pulsar.

This confirms that G292 produced a neutron star through the collapse of the core of a massive star, G292 providing a new and powerful technique of learning more about supernova, due to its asymmetry.

These results will appear in the December 1 issue of The Astrophysical Journal Letters. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass.