January 8, 2013
NASA NuSTAR Catches Glimpse Of Supernova Remnant, Black Holes
redOrbit Staff & Wire Reports - Your Universe Online
NASA has released a pair of new images captured by the Nuclear Spectroscopic Telescope Array (NuSTAR) — one depicting a pair of black holes lurking inside a spiral galaxy, and the other featuring a look at the supernova remnant Cassiopeia A.
“With NuSTAR's greater sensitivity and imaging capability, we're getting a wealth of new information on a wide array of cosmic phenomena in the high-energy X-ray portion of the electromagnetic spectrum,” he added.
The black holes were found in the spiral galaxy IC 342 (also known as Caldwell 5), some seven million light years away from Earth in the constellation Camelopardalis. The black holes were originally discovered at lower-energy X-ray wavelengths by NASA's Chandra X-ray Observatory, but the newly released NuSTAR images are the first focused pictures to feature them in high-energy X-ray light.
“The black holes appear much brighter than typical stellar-mass black holes, such as those that pepper our own galaxy, yet they cannot be supermassive black holes or they would have sunk to the galaxy's center,” researchers from the US space agency explained. “Instead, they may be intermediate in mass, or there may be something else going on to explain their extremely energetic state. NuSTAR will help solve this puzzle.”
Cassiopeia A (Cas A), the supernova remnant featured in the second of the two photos, is located roughly 11,000 light-years away in the constellation Cassiopeia. The remnant is alternately colored blue, red, and green in the picture, with the blue region representing the highest energy X-ray light detected by NuSTAR and the other two colors signifying the bottom end of the array´s energy range.
“The blue region is where the shock wave from the supernova blast is slamming into material surrounding it, accelerating particles to nearly the speed of light. As the particles speed up, they give off a type of light known as synchrotron radiation,” NASA explained. “NuSTAR will be able to determine for the first time how energetic the particles are, and address the mystery of what causes them to reach such great speeds.”
“Cas A is the poster child for studying how massive stars explode and also provides us a clue to the origin of the high-energy particles, or cosmic rays, that we see here on Earth," added Caltech´s Brian Grefenstette, one of the project´s lead researchers. “With NuSTAR, we can study where, as well as how, particles are accelerated to such ultra-relativistic energies in the remnant left behind by the supernova explosion.”
Image 2 (below): This new view of the historical supernova remnant Cassiopeia A, located 11,000 light-years away, was taken by NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR. Blue indicates the highest energy X-ray light, where NuSTAR has made the first resolved image ever of this source. Red and green show the lower end of NuSTAR's energy range, which overlaps with NASA's high-resolution Chandra X-ray Observatory. Credit: NASA/JPL-Caltech/DSS