Launched last June, NuSTAR
is the first orbiting telescope with the ability to focus high-energy
X-ray light. It can view objects in considerably greater detail than
previous missions operating at similar wavelengths. Since launch, the
NuSTAR team has been fine-tuning the telescope, which includes a mast
the length of a school bus connecting the mirrors and detectors.
The new image above showcase why NuSTAR is giving us an unprecedented
look at the cosmos," said Lou Kaluzienski, NuSTAR program scientist at NASA headquarters
in Washington. "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"
The mission has looked at a range of extreme, high-energy objects
already, including black holes near and far, and the incredibly dense
cores of dead stars. In addition, NuSTAR has begun black hole searches
in the inner region of the Milky Way galaxy and in distant galaxies in the universe. *
Among the telescope's targets is the spiral galaxy IC342 above, also known as Caldwell 5,
featured in one of the two new images. This galaxy lies 7 million
light-years away in the constellation Camelopardalis (the Giraffe).
Previous X-ray observations of the galaxy from NASA's Chandra X-ray Observatory
revealed the presence of two blinding black holes, called ultraluminous
X-ray sources (ULXs). *
How ULXs can shine so brilliantly is an ongoing mystery in astronomy.
While these black holes are not as powerful as the supermassive black
hole at the hearts of galaxies, they are more than 10 times brighter
than the stellar-mass
black holes peppered among the stars in our own galaxy. Astronomers
think ULXs could be less common intermediate-mass black holes, with a
few thousand times the mass of our sun, or smaller stellar-mass black
holes in an unusually bright state. A third possibility is that these
black holes don't fit neatly into either category.
"High-energy X-rays hold a key to unlocking the mystery surrounding these objects," said Fiona Harrison, NuSTAR principal investigator at the California Institute of Technology
in Pasadena. "Whether they are massive black holes, or there is new
physics in how they feed, the answer is going to be fascinating." *
In the image, the two bright spots that appear entangled in the arms of
the IC342 galaxy are the black holes. High-energy X-ray light has been
translated into the color magenta, while the galaxy itself is shown in
visible light.
"Before NuSTAR, high-energy X-ray pictures of this galaxy and the two
black holes would be so fuzzy that everything would appear as one
pixel," said Harrison.
The second image below features the well-known, historical supernova
remnant Cassiopeia A, located 11,000 light-years away in the
constellation Cassiopeia. The color blue indicates the highest-energy
X-ray light seen by NuSTAR, while red and green signify the lower end of
NuSTAR'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. 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," said Brian Grefenstette of Caltech, a
lead researcher on the observations. "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"
Source: The
Daily Galaxy via http://www.nasa.gov/nustar
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