Science news black hole.

[alokmohan]

Ray Tracing: Energetic cosmic rays linked to giant black holes<br />Ron Cowen<br /><br />Imagine a single proton smashing into Earth's atmosphere with as much punch as a fast-pitch baseball. For decades, scientists have suspected that protons and other particles with such huge energies, known as ultra-high-energy cosmic rays, arise in the tumultuous surroundings of giant black holes at the centers of galaxies. <br /><br /><br /> <br />CATCHING SOME RAYS. Illustration shows air showers generated by the highest-energy cosmic rays, the most energetic particles known in the universe.<br />S. Swordy/Univ. of Chicago, NASA<br /> <br /><br /><br />Now, the sprawling Pierre Auger Observatory in Argentina has found the first solid evidence linking these exceedingly rare cosmic rays—the most energetic particles in the universe—to supermassive black holes in nearby galaxies. <br /><br />"This is a landmark finding for both cosmic-ray physics and astrophysics," says Auger researcher Paul Mantsch of the Fermi National Accelerator Laboratory in Batavia, Ill. Mantsch and a vast team of researchers from 17 countries describe the findings in the Nov. 9 Science. <br /><br />In the study, the observatory recorded 27 cosmic rays with energies greater than 57 billion billion electron volts (eV). The team found that 20 of these 27 ultra-energetic rays came from points in the sky coinciding with the known locations of active galactic nuclei (AGN). Mantsch and his colleagues say there is less than a 1 percent chance that the alignment between the cosmic rays and the AGN is merely random. The AGN all lie relatively close to the Milky Way, no more than 326 million light-years away. <br /><br />In AGN, black holes feed on swirling disks of gas and dust. As this material spirals into the abyss, it heats up and emits energetic radiation. In addition, AGN typically shoot out enormous jets of high-speed gas. The jets might blast some cosmic rays to energies millions of times as great as those created in the mo