solar radio emission at solar maximum

Solar radio emission at solar maximum

CME development in the corona

M. Pick, D. Maia and Ch. MarquéLESIA, Observatoire de Paris

Cospar 2002

Context

• Nançay Radioheliograph (NRH)– Multiwavelength observations (dm-m)– High cadence < second

• Radio survey– NRH and WAVES/WIND spectrograph (dam-km)

– Use for many objectives

• Coordinated observations– SOHO, TRACE, ACE, WIND, YOHKOH, Ulysse and

Ground facilities (Halpha and radio)– Interest of disk observations

Context

• Flare/CME events– Non thermal emission– Energetic electrons tracers of B field– Search for weak emission often occulted by

NT emission

• CMEs in the absence of large flares– Association with noise storms (NT emission)– Thermal emission and eruptive prominences

Radio signatures

Maia et al., 1999

Fast progression in latitudeFull extend: 9 min ≥1000 km/sSuccessive loop interactionsSuper-alfvenic disturbance

CME lateral expansion

Full expansion < 10 min.Signatures of these interactions step by step. Follow in space and time CME progression

Maia et al., 1999November 06 1997

On-disk event

Pohjolainen et al., 2001

Moreton wavecoronal shock waveM-type IIAssociation in time and space

Full expansion 15 min.

Bastille event

Maia et al. 2001

Proxies of CMEs Lateral progression of CME development in the early stage Full development reached within 10 min. or often lessSimilar shape seen by NRH-LASCO(Gopalswamy and Kundu,1992) Identification of different scenarios Starting point :study of individual events

Maia, Aulanier, S. J. Wang et al., 2002

Cospatial south loopsEast and West Quasi simultaneous

South part of the CME: Breakout type instability Null point 26OOO km, B reconnection, MHD wave triggers activity. S Loops pushing up and interconnecting with multiple B systems.North part of the CME (F sources):Null points western part 6000km

Other class of CME development

Coronal null point

October 25, 2000

Radio signature ofB reconfiguration

Bastian et al., 2001: « Radio CME »Maia et al., 2001 Plasma front , CME-Driven shock

Dynamics of CMEs: Detection of weak NT emissions

Gyrosynchrotron emissionRadio V 1570 ± 390 km/sLASCO V 980± 70 km/sDeacceleration in the corona <4 Rs (Gopalswamy et al., 02)

C2

NRH

C3

C2

Thermal emission and CME development

Marqué et al., 2002

Type III like bursts above the parasitic polarity

Radio depression appears ~40 mn later

Dynamical continuity radio depression and CME substructures

Continuity with radio depression CAVITYOn-disk and limb observations Traces the motion at low altitudeLink between EIT and LASCO

CONCLUSION

Multifrequency radio imaging observationsOn-disk and limb behaviour of CME Link with coronographic observationsPerspective :systematic studies using the survey

CMEs, origin of energetic electron events…

LimitationsNeed of high dynamic range Hardly difficult to observe both weak and strong emissionPresently No sufficient frequency coverage

NEED for FASR

Narrow band horizontal features (Reiner et al;, 2000)

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 agentImportance of the wide spectral range (Klassen, 01)

Role of Moreton wave in flare/CME development

• Moreton wave and coronal m-type II burst

• Subsequent B interaction

Observations: agreement with P.F. Chen et al. (2002)Piston-driven shock along envelope of CMELegs Moreton waveMoving wave-like (enhanced plasma region ahead) EIT wave

succesive opening of B (Delannée et al., 99)

Role of Moreton wave in flare/CME development

Flare/CME events involving multi-magnetic structuresFull expansion < 10 min.

Moreton waves: causal association with CMEs : lateral expansion

BUT NOT ALWAYS Maia et al., 1999; Maia et al, 2001

Moreton waves and Flare/CME events

AD

C E

F

Complex of activity

Filament eruption

Moreton wave, 1400 km/s

Cospatialsouth loops

East and WestQuasi simultaneous

Moreton waves and Flare/CME events

South part of the CME: Breakout type instability

Null point 26OOO km, B reconnection, MHD wave triggers activity. S Loops pushing up and interconnecting with multiple B systems.North part of the CME (F sources):Null points western part 6000kmAlternatively, shock but no evidence in the north partMoreton wave and eruptive prominence no significant role

October 14 1999

Maia, Aulanier, S. J. Wang et al., 2002

Radio event

•Faint type III-like bursts above the parasitic polarity: beginning of the eruption in EIT (slow evolution phase).•Radio depression to appear ~40 mn later (acceleration phase)•Dynamical continuity between radio depression and CME substructures.

AD

C E

F

Cospatialsouth loops

East and WestQuasi simultaneous

South part of the CME: Breakout type instability Null point 26OOO km, B reconnection, MHD wave triggers activity. S Loops pushing up and interconnecting with multiple B systems.

North part of the CME (F sources):Null points western part 6000km

15 April 2001

Dynamics of CMEs: Detection of weak NT emissionsBastian et al., 2001: « Radio CME »(Maia et al., 2001 Plasma front , CME-Driven shock

Moreton waves and flare/CME events• Moreton wave• Pohjolainen, Maia, Pick, Vilmer

et al., 2001

Disk event

• (Bastian et al.,2001)

CME Radio imaging

CME-Driven shockPlasma front (Maia et al., 2001

Detection of weak emissions

eruptive scenario (non thermal/thermal emission), observational continuity between eruptive site and coronagraph f.o.v.

Feb 28th 2002

• Low energetical release event: ~B4 GOES event, faint type III like bursts.• Dark sigmoïd structure for the initial eruptive filament.•Eruption is triggered by the birth of a small parasitic polarity, a few hours before the D.B.

Ref: Marqué, Lantos, Delaboudinière, A&A, 2002, 387,317