April 25, 2013
X-Ray Astronomy Anniversary
This year marks the 50th anniversary of X-ray astronomy and scientists around the globe have been celebrating. The supernova remnant SN 1006 is one of the best celestial objects for illustrating just how far we have come in those 50 years.
The supernova remnant first appeared on May 1, 1006 AD. It was brighter than Venus and visible during the day for weeks. Astronomers in China, Japan, Europe and the Arabic world, documented this event. In the 1960s, dubbed the advent of the Space Age, scientists were able to launch instruments and detectors above the planet’s atmosphere to observe the Universe in wavelengths that are blocked on the ground. These wavelengths include X-rays. At that time, SN 1006 was one of the faintest X-ray sources to be detected by the first generation of X-ray satellites.
A recent image of SN 1006, taken by NASA’s Chandra X-ray Observatory, reveals this exquisite detail of this supernova. Astronomers stitched together ten different overlapping pointings of Chandra’s field-of-view to create a cosmic tapestry of the debris field created when a white dwarf star exploded. The Chandra image reveals low, medium and higher-energy X-rays as red, green and blue respectively.
SN 1006 is what is left of a Type Ia supernova, which is caused when a white dwarf pulls too much mass from a companion star and explodes. A Type Ia could also be created if two white dwarfs merged and then exploded. Type Ia’s are used by astronomers as mileposts to mark the expansion of the universe, making understanding them of tantamount importance.
The new Chandra image gives up the most spatially detailed map to date of the material ejected during a Type Ia supernova. Researchers might be able to piece together how the star looked before it exploded and the order that the layers were ejected by examining the different elements in the debris field. Those elements, including silicon, oxygen and magnesium, might also allow the research team to constrain theoretical models for the explosion.
Using Chandra and other X-ray observatories, astronomers are also able to piece together how fast specific knots of material are moving outward from the original explosion. The fastest bits are moving at approximately 11 billion miles per hour, while slower moving areas are moving away from the remnant at a leisurely seven billion miles per hour. SN 1006 is about 7,000 light years from Earth.
The research team presented their findings, based on over eight days worth of observations from Chandra, at a meeting of the High Energy Astrophysics Division of the American Astronomical Society.
We’ve come a long way since SN 1006 was first observed as a “bright light” in the daytime sky. If we can advance that far in the last 50 years, I can’t wait to see what kind of detail will be visible to us in another 50.
Image Credit: NASA / CXC / Middlebury College / F. Winklerch