Solar Origin of energetic particle events Near-relativistic impulsive electron events observed at 1 AU M. Pick, D. Maia, S.J. Wang, A. Lecacheux, D. Haggery, S. E. Hawkins COSPAR 2002

CONTEXT  Association with radio type III bursts (Lin, 1981) In-situ observations IP type III 2-20 KeV  Above keV  Release often delayed up to 30 min  Krucker et al., 1999: ¾ delayed events associated EIT wave without radio signature 2classes Role of the moving wave front? Triggering or acceleration?  Haggerty et al.: 2001 Acceleration by CME driven shock and injection at about 1Rs  Coronal sites of acceleration  Magnetic restructuring during CME development ( Buttighoffer et al Maia et al., 1999, 2001; Pojholainen et al., 2001: Klein et al., 2001)

DATA ANALYSIS EPAM/ACE keV (Haggerty and Roelof, 2001) 18 February 2002 Pitch angle distribution strongly collimated along IMF At Sun: Intensity maxima no dispersed, scatter- free propagation

DATA ANALYSIS Coronal and IP Radio signatures  Wide spectral coverage  Radio source (dm-m)  5 /11events: complex evolution (spectral, spatial and temporal) WIND DAM NRH 18 February :28

Radio signatures and CME + DAM NRH: 09:19 UT  Source of electrons in region of interaction,  First shock is the triggering agent ( 1400 km/s)  Importance of the wide spectral range (Klassen, 01) V=898 (± 18) km/s t1Rs =09:06 ± 3min UT

May 31, 1999 Coronal and IP Radio signatures  Source of electrons associated with long duration stationary storm in corona. Vicinity of one CME leg (Kerdraon et al., 1983). Access to IP medium  Electrons produced during magnetic reconnection during newly formed streamers? (Kahler and Hundhausen, 1992)

May 01, 2000 is not a CME event Electrons Radio ejecta 1470 km/s V=1335 ± 70 km/s

CONCLUSIONS  Radio signatures found for the 5 « delayed events »  Source of quasi-relativistic electrons associated with reconfiguration of coronal magnetic field during flare/CME events  Present study suggests two kinds with distinct radio signatures  Interaction with some triggering disturbance ( coronal wave, bow shock,….) Consistency with Krucker et al., 1999  Magnetic reconfiguration (post event, long duration). Evidence that electrons escape  Altitude of this region highly variable from one event to the other one  Opening of the magnetic field during CME development  Importance of wide spectral and imaging coverage

Energetic electron beam events November WIND/WAVES NRH E-W plot Three similar radio events located on the western limb. Each event includes two successive type III groups separated by 4 or 5 minutes D. Maia, M. Pick, S. E. Hawkins, S. Krucker, The Astrophys., 500, 1058, 2001

Electron injection 04 April 2000

Near-relativistic solar electron events ACE/EPAM 13:46:32 UT ( min propagation + 500s) Signature Ejecta radio 13:40 UT 750 km/s Near relativistic electrons Injection at 0.42 RS (~15 min delay if onset of EM radiation, no estimate of V shock)

Near-relativistic solar electron events ACE/EPAM 10:23:55 UT ( min propagation + 500s) Signature Ejecta radio 10:21:30 UT 1470 km/s Near relativistic electrons Injection at 0.3 RS 1470 km/S