Solar neutron events of 2003 October-November

Academic Article


  • During the period when the Sun was intensely active on October-November 2003, two remarkable solar neutron events were observed by the ground-based neutron monitors. On October 28, 2003, in association with an X17.2 large flare, solar neutrons were detected with high statistical significance (6.4 sigma) by the neutron monitor at Tsumeb, Namibia. On November 4, 2003, in association with an X28 class flare, relativistic solar neutrons were observed by the neutron monitors at Haleakala in Hawaii and Mexico City, and by the solar neutron telescope at Mauna Kea in Hawaii simultaneously. Clear excesses were observed at the same time by these detectors, with the significance calculated as 7.5 sigma for Haleakala, and 5.2 sigma for Mexico City. The detector onboard the INTEGRAL satellite observed a high flux of hard X-rays and gamma-rays at the same time in these events. By using the time profiles of the gamma-ray lines, we can explain the time profile of the neutron monitor. It appears that neutrons were produced at the same time as the gamma-ray emission.
  • Authors

  • Watanabe, K
  • Gros, M
  • Stoker, PH
  • Kudela, K
  • Lopate, Cliff
  • Valdes-Galicia, JF
  • Hurtado, A
  • Musalem, O
  • Ogasawara, R
  • Mizumoto, Y
  • Nakagiri, M
  • Miyashita, A
  • Matsubara, Y
  • Sako, T
  • Muraki, Y
  • Sakai, T
  • Shibata, S
  • Status

    Publication Date

  • January 10, 2006
  • Has Subject Area

    Published In


  • Sun : X-rays, gamma rays
  • Sun : flares
  • Sun : particle emission
  • acceleration of particles
  • cosmic rays
  • radiation mechanisms : nonthermal
  • Digital Object Identifier (doi)

    Start Page

  • 1135
  • End Page

  • 1144
  • Volume

  • 636
  • Issue

  • 2