lat obserwacji, by wykryć i potwierdzić słaby sygnał dochodzący od M82. "Spodziewaliśmy się, Ŝe wykrycie M82 będzie miało ogromne znaczenie naukowe. Dlatego zaplanowaliśmy wyjątkowo długą ekspozycję natychmiast po tym, jak instrumenty stały się gotowe do badań "mówi Benbow. -"Dane naleŜało szczegółowo przeanalizować aby wydobyć z nich sygnał promieniowania gamma - ponad milion razy słabszy od szumu tła. ChociaŜ zatem sygnał stanowi ułamek danych przeprowadziliśmy wiele analiz potwierdzających jego istnienie i jesteśmy przekonani, Ŝe sygnał jest prawdziwy."
the speed of light. The most energetic cosmic rays hit with the punch of a 98-mph fastball, even though they are smaller than an atom. Astronomers questioned what natural force could accelerate particles to such a speed. New evidence from the VERITAS telescope array shows that cosmic rays likely are powered by exploding stars and stellar "winds." These findings were published in the Nov. 1 online issue of the journal Nature, and are being featured today in a press conference at the Fermi Science Symposium in Washington, DC. Seeking the source of cosmic rays
"Wykrycie M82 wskazuje, iŜ Wszechświat pełen jest naturalnych akceleratorów cząstek. W miarę jak będziemy ulepszać naziemne obserwatoria promieniowania gamma przyjdą kolejne odkrycia "- mówi prof. Martin Pohl. Źródła: Harvard-Smithsonian Center for Astrophysics: VERITAS Telescopes Help Solve 100-Year-Old Mystery: The Origin of Cosmic Rays Zdjęcie: CfA/V.A. Acciari Original press release follows: VERITAS Telescopes Help Solve 100-Year-Old Mystery: The Origin of Cosmic Rays Nearly 100 years ago, scientists detected the first signs of cosmic rays - subatomic particles (mostly protons) that zip through space at nearly
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The rarest cosmic rays carry over 100 billion times as much energy as generated by any particle accelerator on Earth. ("Cosmic ray" is a historical misnomer, since they are individual particles, not a ray or beam.) Astronomers have devised ingenious methods for detecting cosmic rays that hit Earth's atmosphere. However, detecting cosmic rays from a distance requires much more effort.
Smithsonian Astrophysical Observatory. Benbow coordinated this project for the Very Energetic Radiation Imaging Telescope Array System (VERITAS) collaboration. The VERITAS observations strongly support the long-held theory that supernovae and stellar winds from massive stars are the dominant accelerators of cosmic-ray particles. Galaxies with high levels of star formation like M82, also known as "starburst" galaxies, have large numbers of supernovae and massive stars. If the theory holds, then starburst galaxies should contain more cosmic rays than normal galaxies. The VERITAS discovery confirms that expectation, indicating that the cosmic-ray density in M82 is approximately 500 times the average density in our Galaxy, the Milky Way. "This discovery provides fundamental insight into the origin of cosmic rays," said Rene Ong, a professor of physics at the University of California, Los Angeles, and the spokesperson for the VERITAS collaboration. Using gamma rays to infer cosmic rays
VERITAS has found new evidence for cosmic rays in the "Cigar Galaxy," also known as Messier 82 (M82), which is located 12 million light-years from Earth in the direction of the constellation Ursa Major. "This discovery has been predicted for almost 20 years, but until now no instrument was sensitive enough to see it," said Wystan Benbow, an astrophysicist at the
VERITAS could not detect M82's cosmic rays directly because they are trapped within the Cigar Galaxy. Instead, VERITAS looked for clues to the presence of cosmic rays: gamma rays. Gamma rays are the most energetic form of light, far more powerful than ultraviolet light or even X-rays. When cosmic rays interact with interstellar