PRELIMINARY onset time analysis of ISEE 3 Energetic Electron Events

• onset times and error bars are approximated from plots by hand
• there are 3 different ways the energy (i.e. the inverse velocity) is determined:
  • energy=maximum energy in bin
  • energy=averaged energy in bin
  • energy=minimum energy in bin
• if the event is strong, 'energy=maximum energy in bin' is the best assumption. however, for weak events, it might be possible that there are not enough electrons at the maximum energy in the bin (spectrum is steep), and the actual onset is produced by electrons at lower energies.
• therefore, there are 3 values of the relative timing in the table below. clicking to each of these values in the table brings up a plot showing
  • top: onset time of the electrons at 1 AU relative to the start of the radio spikes at the Sun (hence, 500 seconds are subtracted) as a function of inverse velocity. the blue dashed line shows the expected onset times for electrons released at the time the spikes occur at the Sun assuming a path length of 1.2 AU. the red line is a linear fit to the observed onset times. only points marked with a red cross are used in the fit.
  • bottom: the solar release times are approximated assuming again a path length of 1.2 AU and plotted as a function of energy. t=0 corresponds again to the time of the spike event.
• the column 'onset times at xxx-xxx keV' gives information about the onset:
  • ok=clear onset
  • no=no enhanced flux
  • unclear=there is an event, but the onset is hard to determine