Cosmological origin for cosmic rays above 10**19-eV

Aug, 1995
9 pages
Published in:
  • Astrophys.J.Lett. 452 (1995) L1-L4
e-Print:
Report number:
  • IASSNS-AST-95-32

Citations per year

1995200220092016202302468101214
Abstract: (arXiv)
The cosmic ray spectrum at 10 19eV10 20eV10~{19}{\rm eV}-10~{20}{\rm eV}, reported by the Fly's Eye and the AGASA experiments, is shown to be consistent with a cosmological distribution of sources of protons, with a power law generation spectrum dlnN/dlnE=2.3±0.5{\rm d}\ln N/{\rm d}\ln E=-2.3\pm0.5 and energy production rate of 4.5±1.5×10 44erg Mpc 3 yr 14.5\pm1.5\times10~{44}{\rm erg}\ {\rm Mpc}~{-3}\ {\rm yr}~{-1}. The two events measured above 10 20eV10~{20}{\rm eV} are not inconsistent with this model. Verifying the existence of a ``black-body cutoff'', currently observed with low significance, would require 30\sim30 observation-years with existing experiments, but only 1\sim1 year with the proposed 5000 km 2\sim5000\ {\rm km}~2 detectors. For a cosmological source distribution, no anisotropy is expected in the angular distribution of events with energies up to 5×10 19eV\sim5\times10~{19}{\rm eV}.
  • cosmic radiation: primary
  • cosmic radiation: energy spectrum
  • energy spectrum: cosmic radiation
  • cosmic radiation: flux
  • flux: cosmic radiation
  • cosmic radiation: hadronic component
  • cosmic radiation: particle source
  • cosmic radiation: acceleration
  • numerical calculations: interpretation of experiments
  • > 10**10 GeV