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A step closer in the Search of Cosmic Rays Origin

Cosmic rays, high-energy particles, can damage electronics on Earth, as well as human and non-human DNA, which puts astronauts in space at risk but has also caused any number of genetic modifications in plants that are considered completely natural.

Their origin has confounded scientists for decades. A study using data  collected by IceTop at the IceCube Neutrino Observatory at the South Pole, reveals new information that may help unravel the longstanding mystery of exactly how and where these "rays", because the more scientists learn about the energy spectrum and chemical composition of cosmic rays, the closer humanity will come to uncovering where these energetic particles originate.
Cosmic rays are known to reach energies above 100 billion giga-electron volts (1011 GeV). The data reported in this latest paper cover the energy range from 1.6 times 106 GeV to 109 GeV. Researchers are particularly interested in identifying cosmic rays in this interval because the transition from cosmic rays produced in the Milky Way Galaxy to "extragalactic" cosmic rays, produced outside our galaxy, is expected to occur in this energy range.

The cosmic ray energy spectrum, shows the steepening at the "knee." Below the knee, cosmic rays are galactic in origin; above that energy, particles from more distant regions in our universe become more and more likely. Credit: Bakhtiyar Ruzybayev/University of Delaware
Exploding stars called supernovae are among the sources of cosmic rays here in the Milky Way, while distant objects such as collapsing massive stars and active galactic nuclei far from the Milky Way are believed to produce the highest energy particles in nature.

As University of Delaware physicist Bakhtiyar Ruzybayev, the study's corresponding author, points out in the scientific figure (above) submitted to the journal, the cosmic-ray energy spectrum does not follow a simple power law between the "knee" around 4 PeV (peta-electron volts) and the "ankle" around 4 EeV (exa-electron volts), as previously thought, but exhibits features like hardening around 20 PeV and steepening around 130 PeV.

"The spectrum steepens at the 'knee,' which is generally interpreted as the beginning of the end of the galactic population. Below the knee, cosmic rays are galactic in origin, while above that energy, particles from more distant regions in our universe become more and more likely," Ruzybayev explained. "These measurements provide new constraints that must be satisfied by any models that try to explain the acceleration and propagation of cosmic rays."

Citation:  Aartsen, M. G. and Abbasi, R. and Abdou, Y. and Ackermann, M. and Adams, J. and Aguilar, J. A. and Ahlers, M. and Altmann, D. and Auffenberg, J. and Bai, X. and Baker, M. and Barwick, S. W. and Baum, V. and Bay, R. and Beatty, J. J. and Bechet, S. and Becker Tjus, J. and Becker, K.-H. and Benabderrahmane, M. L. and BenZvi, S. and Berghaus, P. and Berley, D. and Bernardini, E. and Bernhard, A. and Bertrand, D. and Besson, D. Z. and Binder, G. and Bindig, D. and Bissok, M. and Blaufuss, E. and Blumenthal, J. and Boersma, D. J. and Bohaichuk, S. and Bohm, C. and Bose, D. and B\"oser, S. and Botner, O. and Brayeur, L. and Bretz, H.-P. and Brown, A. M. and Bruijn, R. and Brunner, J. and Carson, M. and Casey, J. and Casier, M. and Chirkin, D. and Christov, A. and Christy, B. and Clark, K. and Clevermann, F. and Coenders, S. and Cohen, S. and Cowen, D. F. and Cruz Silva, A. H. and Danninger, M. and Daughhetee, J. and Davis, J. C. and De Clercq, C. and De Ridder, S. and Desiati, P. and de Vries, K. D. and de With, M. and DeYoung, T. and D\'\iaz-V\'elez, J. C. and Dunkman, M. and Eagan, R. and Eberhardt, B. and Eisch, J. and Ellsworth, R. W. and Euler, S. and Evenson, P. A. and Fadiran, O. and Fazely, A. R. and Fedynitch, A. and Feintzeig, J. and Feusels, T. and Filimonov, K. and Finley, C. and Fischer-Wasels, T. and Flis, S. and Franckowiak, A. and Frantzen, K. and Fuchs, T. and Gaisser, T. K. and Gallagher, J. and Gerhardt, L. and Gladstone, L. and Glusenkamp, T. and Goldschmidt, A. and Golup, G. and Gonzalez, J. G. and Goodman, J. A. and G'ora, D. and Grandmont, D. T. and Grant, D. and Groß, A. and Ha, C. and Haj Ismail, A. and Hallen, P. and Hallgren, A. and Halzen, F. and Hanson, K. and Heereman, D. and Heinen, D. and Helbing, K. and Hellauer, R. and Hickford, S. and Hill, G. C. and Hoffman, K. D. and Hoffmann, R. and Homeier, A. and Hoshina, K. and Huelsnitz, W. and Hulth, P. O. and Hultqvist, K. and Hussain, S. and Ishihara, A. and Jacobi, E. and Jacobsen, J. and Jagielski, K. and Japaridze, G. S. and Jero, K. and Jlelati, O. and Kaminsky, B. and Kappes, A. and Karg, T. and Karle, A. and Kelley, J. L. and Kiryluk, J. and Klas, J. and Klein, S. R. and Kohne, J.-H. and Kohnen, G. and Kolanoski, H. and Kopke, L. and Kopper, C. and Kopper, S. and Koskinen, D. J. and Kowalski, M. and Krasberg, M. and Krings, K. and Kroll, G. and Kunnen, J. and Kurahashi, N. and Kuwabara, T. and Labare, M. and Landsman, H. and Larson, M. J. and Lesiak-Bzdak, M. and Leuermann, M. and Leute, J. and Lunemann, J. and Maciias, O. and Madsen, J. and Maggi, G. and Maruyama, R. and Mase, K. and Matis, H. S. and McNally, F. and Meagher, K. and Merck, M. and Meures, T. and Miarecki, S. and Middell, E. and Milke, N. and Miller, J. and Mohrmann, L. and Montaruli, T. and Morse, R. and Nahnhauer, R. and Naumann, U. and Niederhausen, H. and Nowicki, S. C. and Nygren, D. R. and Obertacke, A. and Odrowski, S. and Olivas, A. and Omairat, A. and O' Murchadha, A. and Paul, L. and Pepper, J. A. and Perez de los Heros, C. and Pfendner, C. and Pieloth, D. and Pinat, E. and Posselt, J. and Price, P. B. and Przybylski, G. T. and Radel, L. and Rameez, M. and Rawlins, K. and Redl, P. and Reimann, R. and Resconi, E. and Rhode, W. and Ribordy, M. and Richman, M. and Riedel, B. and Rodrigues, J. P. and Rott, C. and Ruhe, T. and Ruzybayev, B. and Ryckbosch, D. and Saba, S. M. and Salameh, T. and Sander, H.-G. and Santander, M. and Sarkar, S. and Schatto, K. and Scheriau, F. and Schmidt, T. and Schmitz, M. and Schoenen, S. and Schoneberg, S. and Schonwald, A. and Schukraft, A. and Schulte, L. and Schulz, O. and Seckel, D. and Sestayo, Y. and Seunarine, S. and Shanidze, R. and Sheremata, C. and Smith, M. W. E. and Soldin, D. and Spiczak, G. M. and Spiering, C. and Stamatikos, M. and Stanev, T. and Stasik, A. and Stezelberger, T. and Stokstad, R. G. and Stößl, A. and Strahler, E. A. and Ström, R. and Sullivan, G. W. and Taavola, H. and Taboada, I. and Tamburro, A. and Tepe, A. and Ter-Antonyan, S. and G. Tešić and Tilav, S. and Toale, P. A. and Toscano, S. and Unger, E. and Usner, M. and Vallecorsa, S. and van Eijndhoven, N. and Van Overloop, A. and van Santen, J. and Vehring, M. and Voge, M. and Vraeghe, M. and Walck, C. and Waldenmaier, T. and Wallraff, M. and Weaver, Ch. and Wellons, M. and Wendt, C. and Westerhoff, S. and Whitehorn, N. and Wiebe, K. and Wiebusch, C. H. and Williams, D. R. and Wissing, H. and Wolf, M. and Wood, T. R. and Woschnagg, K. and Xu, C. and Xu, D. L. and Xu, X. W. and Yanez, J. P. and Yodh, G. and Yoshida, S. and Zarzhitsky, P. and Ziemann, J. and Zierke, S. and Zoll, M.,IceCube Collaboration, 'Measurement of the cosmic ray energy spectrum with IceTop-73', Phys. Rev. D » Volume 88 » Issue 4 DOI: 10.1103/PhysRevD.88.042004

Posted by Omkarr singh on Saturday, August 31, 2013. Filed under , , . You can follow any responses to this entry through the RSS 2.0

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