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 25-50 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. 1996

Maia et al., 1999, 2001; Pojholainen et al., 2001: Klein et al., 2001)

DATA ANALYSISEPAM/ACE 38-315 keV (Haggerty and Roelof, 2001)

18 February 2002Pitch angle distribution strongly collimated along IMF

At Sun: Intensity maxima no dispersed, scatter- free propagation

DATA ANALYSISCoronal and IP Radio signatures

Wide spectral coverage

Radio source (dm-m)

5 /11events: complex evolution (spectral, spatial and temporal)

WIND

DAM

NRH

18 February 2000

09:28

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/st1Rs =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 mediumElectrons produced during magnetic reconnection during newly formed streamers? (Kahler and Hundhausen, 1992)

May 01, 2000 is not a CME event

Electrons

Radio ejecta

Radio ejecta1470 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 28 1997

WIND/WAVES

NRHE-W plot

Three similar radio events located on the western limb. Each event includes two successive type III groups separatedby 4 or 5 minutesD. 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 ( - 13.7 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 ( - 13.7 min propagation + 500s)

Signature Ejecta radio 10:21:30 UT 1470 km/s

Near relativistic electrons Injection at 0.3 RS

1470 km/S