Chandra X-Ray Observatory


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Chandra X-Ray Observatory

An orbiting X-ray astronomy observatory launched by NASA in July 1999 as the third of its Great Observatories. Chandra, which takes its name from the 20th-century Indian-born US astrophysicist Subrahmanyan Chandrasekhar, was originally developed as one of the craft making up NASA's Advanced X-Ray Astrophysics Facility (see AXAF); dubbed AXAF-I and renamed after its launch, Chandra was equipped for high-resolution X-ray imaging and was deployed by the space shuttle Columbia into a highly eccentric orbit (apogee 140 161 km, inclination 28.5°) that has allowed long periods of observation unimpeded by Earth shadowing. Chandra's optics consist of four nested pairs of grazing incidence paraboloid and hyperboloid mirrors, each having an outer diameter of 1.2 meters and a focal length of 10 meters. With its Advanced Charged Couple Imaging Spectrometer (ACIS) and its high-resolution camera using large field-of-view microchannel plates to make X-ray images, Chandra's optical system achieves an angular resolution of 0.5 arcseconds over an operating range of 0.2–10 keV. Its high- and low-energy transmission gratings provide impressive spectral resolution throughout the range 0.09–10 keV.

Chandra has been called the most sophisticated X-ray observatory of its time, providing images of unprecedented detail at resolutions that are claimed to be about 50 times better than those achieved by ROSAT, the best X-ray astronomy satellite prior to 1999. In its first five years, Chandra has begun to penetrate the hottest, most energetic regions of the Universe. In particular, it has advanced our knowledge of black holes, discovering among many other things how fast they spin, finding evidence of a star torn apart by a black hole, and emphatically confirming the reality of the event horizon. It has revealed enormous tracts of hot gas, billions of parsecs distant and radiating at temperatures of tens of millions of degrees K. It has provided startling new images of supernova remnants such as the Crab Nebula, with its restless pulsar, showing intricate details never suspected before. It has made new studies of star-forming regions such as the Orion Nebula and analyzed the effects of galaxy collisions and the merging of galaxy clusters. Most notably, it has gathered direct evidence of dark energy and the expansion of the Universe.

References in periodicals archive ?
PHOTO A computer image shows the Chandra X-ray Observatory as it will look in orbit more than 6,000 miles up.
Where Swift's BAT provided a wide-angle view, the X-ray telescope aboard the Chandra X-ray Observatory acted like a zoom lens and resolved details a hundred times smaller.
In this 199-hour portrait, recorded with NASA's Chandra x-ray Observatory, red denotes the lowest-energy X rays, blue the highest.
Papers from a summer 2003 symposium reflect recent research in neutron star properties made possible by the Chandra X-Ray Observatory and the XMM-Newton mission.
Manchisi noted that Kodak has partnered with NASA on space science and remote sensing missions for more than 40 years, including the Lunar Orbiter missions and the Chandra X-ray observatory.
The space agency's Chandra X-ray Observatory found 110 sources of X-ray in IC 10, of which over 40 can be seen in visible light as well.
As one of the first objects observed by NASA's Chandra X-ray Observatory after its launch some 15 years ago, this double star system continues to reveal new clues about its nature through the X-rays it generates.
Washington, June 4 ( ANI ): Researchers observed million seconds of observing time with NASA's Chandra X-ray Observatory and discovered a spiral galaxy similar to the Milky Way glittering with hundreds of X-ray points of light.
Below, an X-ray image from the Chandra X-ray Observatory (blue) is overlaid on a visible-light image of the elliptical galaxy NGC 1399 (mostly hidden in the X-ray glare).
NASA's Chandra X-ray Observatory has detected X rays from the core of NGC 1365, but the proposed disk would be too small for the craft to discern directly.
Both are based on TRW's advanced pintle injector concept and share heritage with TRW's reliable Lunar Module Descent Engine and the 100-pound thrust engine used to insert NASA's Chandra X-ray Observatory into a highly elliptical orbit.
Then, quite mysteriously, it faded completely, falling below the sensitivity NASA's Chandra X-ray Observatory is capable of detecting.