Solar Radio Monitoring at Nançay Observatory - spectrography and imaging K.-L. Klein, A. Kerdraon, A. Lecacheux

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) Kerdraon, Pick, Hoang, Wang, Haggerty 2010 ApJ 715, 468 Wind/WAVES Nançay DA ARTEMIS Nançay RH Radio monitoring of the eruptive Sun What do we see ? Type IV (trapped e) Solar Radio Monitoring at Nançay2

At ≥ dm-λ waves: emission at ν~ν pe ~√n e – 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) Kerdraon, Pick, Hoang, Wang, Haggerty 2010 ApJ 715, 468 Wind/WAVES Nançay DA ARTEMIS Nançay RH Radio monitoring of the eruptive Sun What do we see ? Type IV (trapped e) trapped e e beam shock Frequency [MHz] Time (altitude) IIIII IV Solar Radio Monitoring at Nançay3

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) Kerdraon, Pick, Hoang, Wang, Haggerty 2010 ApJ 715, 468 Type III Type II STEREO + NRH Radio monitoring of the eruptive Sun What do we see ? Flaring AR Type II (shock wave) Wind/WAVES Nançay DA ARTEMIS Nançay RH Solar Radio Monitoring at Nançay4

2 historical instruments: – Radioheliograph (NRH; MHz; only solar- dedicated imager at dm-m- ) – Decametre Array (NDA; MHz; unparalleled sensitivity and data quality; new digital receiver) New spectrograph: ORFEES, completes spectrographic coverage to 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 instrumentation Nançay Observatory space Nançay Spectral identification of mapped sources Solar Radio Monitoring at Nançay5

Solar-dedicated radio instrumentation Distribution of Nançay data French solar monitoring data: BASS2000 ( SEPServer project: Particle and EM data for SEP events (server.sepserver.eu)server.sepserver.eu Release of SEPServer this afternoon, splinter meeting 17:15-18:45, Scala 3 ! Radio-dedicated database, in relation with STEREO/SECCHI ( – 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 Nançay6

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 Some can be delivered in real time. Nançay: unique complementary data set in spectrography ( MHz – continuation of spaceborne observations < 14 MHz) & imaging ( MHz) in the corona up to ≈1 R  above the photosphere. Data provision for research ( 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 Nançay7