成人大片

• Research Interests

  Ultra-high energy cosmic rays. These are the most energetic particles known in Nature, and we are part of a large international collaboration formed to determine the origin of these particles. The cosmic rays of interest are incredibly energetic (in excess of 10^19 electron-volts) but they are also incredibly rare (less than 1 particle per square kilometre per year), so detectors must be large. The Pierre Auger Observatory, situated in western Argentina, monitors an area of 3000 square kilometres 24 hours per day looking for interactions of the highest energy cosmic rays. We are building up a large data set that will allow us to identify likely astrophysical sources of these particles, and to understand the extreme processes which accelerate the particles to enormous energies.

  Our specific contributions to the Pierre Auger Observatory include leadership in the analysis of data from the air fluorescence detectors of Auger, monitoring the 3000 square kilometres of area for night-time cloud, and in the astrophysical interpretation of the data through arrival direction and mass composition studies. Further details can be found at the Adelaide astrophysics home page at

• Publications

  A publication listing can be sourced via SPIRES at

  Some Key Publications

  • J. Abraham et al. [Pierre Auger Collaboration], ``Evidence for suppression of the flux of cosmic rays above 4 x 10^19 eV", Physical Review Letters 101 061101 (2008)

  • M. Unger, B.R. Dawson, R. Engel, F. Schussler and R. Ulrich, ``Reconstruction of Longitudinal Profiles of Ultra-High Energy Cosmic Ray Showers from Fluorescence and Cherenkov Light Measurements'', Nuclear Instruments & Methods A 588 433-441 (2008)

  • J. Abraham et al. [Pierre Auger Collaboration], ``Correlation of the highest energy cosmic rays with nearby extragalactic objects", Science 318, 939 (2007)

  • R. U. Abbasi et al. [High Resolution Fly's Eye Collaboration],``A study of the composition of ultra high energy cosmic rays using the High Resolution Fly's Eye,'' Astrophys. J. 622, 910 (2005)

  • R. U. Abbasi et al. [High Resolution Fly's Eye Collaboration], ``Monocular measurement of the spectrum of UHE cosmic rays by the FADC detector of the HiRes experiment'', Astropart. Phys. 23, 157-174 (2005)

  • J. Abraham et al. [Pierre Auger Collaboration], ``Properties and performance of the prototype instrument for the Pierre Auger Observatory'', Nucl. Instrum. Meth. 523A, 50-95 (2004)

  • T. Abu-Zayyad et al. [The High Resolution Fly's Eye Collaboration (HiRes)] ``Measurement of the Flux of Ultrahigh Energy Cosmic Rays from Monocular Observations by the High Resolution Fly's Eye Experiment'', Phys. Rev. Lett. 92, Art. No. 151101 (2004)

  • T.Abu-Zayyad et al. [The High Resolution Fly's Eye Collaboration (HiRes)] ``Measurement of the Cosmic Ray Energy Spectrum and Composition from 10^17 to 10^18.3 eV Using a Hybrid Fluorescence Technique'' Ap. J. 557 686-699 (2001)

  • J.A. Bellido, R.W. Clay, B.R. Dawson and M. Johnston-Hollitt, ``Southern Hemisphere Observations of a 10^18 eV Cosmic Ray Source Near the Direction of the Galactic Centre'', Astropart. Phys. 15, 167-175 (2001)

  • Dawson,B.R., Meyhandan,R. and Simpson,K.M., ``A Comparison of Cosmic Ray Composition Measurements at the Highest Energies'', Astropart. Phys., 9 331-338 (1998)

  • Clay R.W. and Dawson B.R., ``Cosmic Bullets - High Energy Particles in Astrophysics'' (Book), (Allen and Unwin, Sydney, 1997; Addison-Wesley, Reading, Mass. 1998; also published in Chinese and Spanish language versions).

  • Dawson,B.R., Dai,H.Y., Sommers,P. and Yoshida,S., ``Simulations of a Giant Hybrid Air Shower Detector'', Astropart. Phys. 5, 239-247 (1996).

  • Bird,D.J., Corbato,S.C., Dai,H.Y., Dawson,B.R., Elbert,J.W., Emerson,B., Huang,M.A., Kieda,D.B., Luo,M., Ko,S., Larsen,C., Loh,E.C., Salamon,M.H., Smith,J.D., Sokolsky,P., Sommers,P., Tang,J., and Thomas,S.B. ``The Cosmic Ray Energy Spectrum Observed by the Fly's Eye'' Ap.J. 424, 491 (1994)
    

  • Bird,D.J., Corbato,S.C., Dai,H.Y., Dawson,B.R., Elbert,J.W., Gaisser,T.K., Green,K.D., Huang,M.A., Kieda,D.B., Ko,S., Larsen,C., Loh,E.C., Luo, M., Salamon,M.H., Smith,J.D., Sokolsky,P., Sommers,P., Stanev,T., Tang,J., Thomas,S.B., and Tilav,S. ``Evidence for Correlated Changes in the Spectrum and Composition of Cosmic Rays at Extremely High Energies'' Phys. Rev. Lett. 71, 3401 (1993)

  • Gaisser,T.K., Stanev,T., Tilav,S., Corbato,S.C., Dai,H.Y., Dawson,B.R., Elbert,J.W., Emerson,B., Kieda,D.B., Luo,M., Ko,S., Larsen,C., Loh,E.C., Salamon,M.H., Smith,J.D., Sokolsky,P., Sommers,P., Tang,J., Thomas,S.B., and Bird,D.J., ``Cosmic ray composition around 10^18 eV'' Phys. Rev. D 47, 1919 (1993)

  • Sokolsky,P., Sommers,P., and Dawson,B.R, ``Extremely-High Energy Cosmic Rays'', Physics Reports 217, 225-277 (1992)

Entry last updated: Thursday, 12 Jan 2023

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