Solar Radio Monitoring at Nanay Observatory spectrography and
Solar Radio Monitoring at Nançay Observatory spectrography and imaging K. -L. Klein, A. Kerdraon, A. Lecacheux (ludwig. klein@obspm. fr)
Radio monitoring of the eruptive Sun What do we see ? Kerdraon, Pick, Hoang, Wang, Haggerty 2010 Ap. J 715, 468 Type III (e beams) • At dm-m-λ radio waves: Wind/WAVES Type II (shock wave) Nançay DA – 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) Type IV (trapped e) ARTEMIS Nançay RH • Space-weather relevant processes where radio spectrogaphy and imaging provide early information ! Solar Radio Monitoring at Nançay 2
Radio monitoring of the eruptive Sun What do we see ? • At ≥ dm-λ waves: emission at ν~νpe~√ne Wind/WAVES – Propagating exciter in a quasi-static atmosphere or expanding loops (CME): Type II (shock wave) shock Nançay DA e beam trapped e Type IV (trapped e) ARTEMIS – Characteristic shapes of the radio burst spectra: Nançay RH Solar Radio Monitoring at Nançay Frequency [MHz] Kerdraon, Pick, Hoang, Wang, Haggerty 2010 Ap. J 715, 468 Type III (e beams) III II IV Time (altitude) 3
Radio monitoring of the eruptive Sun What do we see ? Kerdraon, Pick, Hoang, Wang, Haggerty 2010 Ap. J 715, 468 Type III (e beams) Wind/WAVES Type II (shock wave) Nançay DA ARTEMIS • 2007 May 19: SEP event (STEREO) • Why does this poorly connected solar activity (EUV: W 05°) emit SEPs detected at Earth (Parker spiral W 38°) ? • 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 II Flaring AR Nançay RH Type III Solar Radio Monitoring at Nançay STEREO + NRH 4
Solar-dedicated radio instrumentation Nançay Observatory • 2 historical instruments: – Radioheliograph (NRH; 150 -450 MHz; only solardedicated imager at dm-m ) – Decametre Array (NDA; 2070 MHz; unparalleled sensitivity and data quality; new digital receiver) • • space New spectrograph: ORFEES, completes spectrographic coverage to 130 -1000 MHz, including NRH frequencies (since 2012; coop. French Air Force) Spectral identification of mapped sources Nançay New extension of NDA to 5 MHz: continuous coverage to space-based observations (Wind/WAVES, STEREO/SWAVES; since 2012) Solar Radio Monitoring at Nançay 5
Solar-dedicated radio instrumentation Distribution of Nançay data • Solar monitoring data: BASS 2000 (http: //bass 2000. 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 6
Solar Radio Monitoring at Nançay Observatory Summary & 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) Solar Radio Monitoring at Nançay 7
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