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Cobalt And Calcium

December 8, 2009 by · Comments Off on Cobalt And Calcium 

blackholexraysCobalt And Calcium: Due to their violent nature and long distance from Earth, black holes and their surroundings are very difficult to study. Currently, the main method to observe a black hole is to use an X-ray satellite to detect the X-ray fluorescence emitted by a black hole’s companion star as the star’s material falls into the black hole. But now, scientists have developed a laser-driven method to generate a flash of brilliant Planckian X-rays in the lab that can be used to simulate the X-rays that exist near black holes. The new results contrast with the generally accepted explanation for the origins of these astronomical features, and may also help scientists test the complex computer codes used in X-ray astronomy.

The team of researchers, Shinsuke Fujioka, et al., from Osaka University, the Chinese Academy of Sciences, the Korea Atomic Energy Research Institute, and Shanghai Jiao Tong University, have published their study on creating Planckian X-rays in the laboratory in a recent issue of Nature Physics.

In their study, the researchers used a direct laser-driven implosion to create a hot, dense plasma. They aimed 12 intense laser beams (for a total of 3 billion watts, and carrying 4.0 kJ [kilojoules] of energy) onto a micrometer-sized spherical hollow plastic shell. When the shell’s core imploded, its temperature approached 1 keV (kiloelectronvolt), creating a hot plasma. With other adjustments to the set-up, the researchers could produce a slowly expanding, cool plasma, much like the astronomical plasma observed near black holes. In the laboratory-generated plasma, the researchers detected the emitted X-rays and measured their spectra.

They identified two characteristic spectral peaks that closely resemble the spectral peaks observed in the binary systems Cygnus X-3 and Vela X-1. In the model of Cygnus X-3, which consists of a black hole and a companion star, the gravitational energy of the star’s accreting material is converted into thermal energy, which is the origin of the radiation emitted by the accretion disk. The X-ray spectra of Cygnus X-3 was previously observed by an X-ray spectrometer onboard the Chandra X-ray satellite.

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