solar radio monitoring at nançay observatory - spectrography and imaging
DESCRIPTION
Solar Radio Monitoring at Nançay Observatory - spectrography and imaging. K.-L. Klein, A. Kerdraon , A. Lecacheux ( ludwig.klein@obs p m.fr ). At dm-m- λ radio waves : Electron beams rising from the low corona to IP space (type III; r ≈ 1.1 R -1 AU) - PowerPoint PPT PresentationTRANSCRIPT
Solar Radio Monitoring at Nançay Observatory -
spectrography and imaging
K.-L. Klein, A. Kerdraon, A. Lecacheux([email protected])
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
• 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)