Solar Radio Monitoring at Nançay Observatory -

spectrography and imaging

K.-L. Klein, A. Kerdraon, A. Lecacheux(ludwig.klein@obspm.fr)

Solar Radio Monitoring at Nançay 2

• At dm-m-λ radio waves:

– Electron beams rising from the low corona to IP space (type III; r ≈ 1.1 R -1 AU)

– Shock waves in the corona and IP space

– Confined electron populations as tracers of CMEs (type IV)

• Space-weather relevant processes where radio spectrogaphy and imaging provide early information !

Type III (e beams)

Type II (shock wave)

Kerd

raon

, Pic

k, H

oang

, Wan

g, H

agge

rty

2010

ApJ

715

, 468

Wind/WAVES

Nançay DA

ARTEMIS

Nançay RH

Radio monitoring of the eruptive SunWhat do we see ?

Type IV (trapped e)

Solar Radio Monitoring at Nançay 3

• At ≥ dm-λ waves: emission at ν~νpe~√ne

– Propagating exciter in a quasi-static atmosphere or expanding loops (CME):

– Characteristic shapes of the radio burst spectra:

Type III (e beams)

Type II (shock wave)

Kerd

raon

, Pic

k, H

oang

, Wan

g, H

agge

rty

2010

ApJ

715

, 468

Wind/WAVES

Nançay DA

ARTEMIS

Nançay RH

Radio monitoring of the eruptive SunWhat do we see ?

Type IV (trapped e)

trapped ee beam

shock

Freq

uenc

y [M

Hz]

Time (altitude)

IIIII

IV

Solar Radio Monitoring at Nançay 4

• 2007 May 19: SEP event (STEREO)• Why does this poorly connected solar

activity (EUV: W05°) emit SEPs detected at Earth (Parker spiral W38°) ?

• Radio imaging (NRH): because the energetic electrons (particles in general ?) are released well westward of the parent AR (shock and open flux tube geometry) !

Type III (e beams)

Kerd

raon

, Pic

k, H

oang

, Wan

g, H

agge

rty

2010

ApJ

715

, 468

Type III

Type II

STEREO + NRH

Radio monitoring of the eruptive SunWhat do we see ?

Flaring AR

Type II (shock wave)

Wind/WAVES

Nançay DA

ARTEMIS

Nançay RH

5

• 2 historical instruments:– Radioheliograph (NRH; 150-

450 MHz; only solar-dedicated imager at dm-m-)

– Decametre Array (NDA; 20-70 MHz; unparalleled sensitivity and data quality; new digital receiver)

• New spectrograph: ORFEES, completes spectrographic coverage to 130-1000 MHz, including NRH frequencies (since 2012; coop. French Air Force)

• New extension of NDA to 5 MHz: continuous coverage to space-based observa-tions (Wind/WAVES, STEREO/SWAVES; since 2012)

Solar-dedicated radio instrumentationNançay Observatory

space

NançaySpectral identification of mapped sources

Solar Radio Monitoring at Nançay

Solar Radio Monitoring at Nançay 6

Solar-dedicated radio instrumentationDistribution of Nançay data

• French solar monitoring data: BASS2000 (http://bass2000.obspm.fr/)

• SEPServer project: Particle and EM data for SEP events (server.sepserver.eu)

• Release of SEPServer this afternoon, splinter meeting 17:15-18:45, Scala 3 !

• Radio-dedicated database, in relation with STEREO/SECCHI (http://secchirh.obspm.fr/):– Spectrographic data Nançay,

ARTEMIS (Greece), Wind/WAVES, STEREO/WAVES)

– NRH overview movies– Underway to 24 h coverage in

radio spectrography (Kunming, Culgoora, …)

Solar Radio Monitoring at Nançay 7

Solar Radio Monitoring at Nançay ObservatorySummary & conclusion

• Radio observations of solar eruptive activity trace potentially geo-effective dynamical phenomena in the corona: escaping energetic particle beams, shock waves, CMEs (on the disk or at the limb).

• Spectrographic data are available from several stations in Europe and worldwide (cf. CESRA website http://lesia.obspm.fr/cesra/).

• Some can be delivered in real time.

• Nançay: unique complementary data set in spectrography (5-1000 MHz – continuation of spaceborne observations < 14 MHz) & imaging (150-450 MHz) in the corona up to ≈1 R above the photosphere.

• Data provision for research (http://secchirh.obspm.fr/) and space weather applications (FEDOME space weather demonstrator, French Air Force).

• Data available for future common services in Europe (cf. Spa. Sit. Aw. questionnaire)