70 likes | 326 Views
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)
E N D
Solar Radio Monitoring atNançay Observatory -spectrography and imaging K.-L. Klein, A. Kerdraon, A. Lecacheux (ludwig.klein@obspm.fr)
At dm-m-λradio waves: Electron beamsrisingfrom the low corona to IP space (type III; r ≈ 1.1 R -1 AU) Shockwaves in the corona and IP space Confinedelectron populations as tracers of CMEs (type IV) Space-weather relevant processeswhere radio spectrogaphy and imagingprovideearly information ! Radio monitoring of the eruptive Sun What do wesee ? Type III (e beams) Wind/WAVES Type II (shockwave) Nançay DA Kerdraon, Pick, Hoang, Wang, Haggerty 2010 ApJ 715, 468 Type IV (trapped e) ARTEMIS Nançay RH Solar Radio Monitoring at Nançay
At ≥ dm-λwaves: emissionatν~νpe~√ne Propagating exciter in a quasi-staticatmosphere or expandingloops (CME): Characteristicshapes of the radio burstspectra: Radio monitoring of the eruptive Sun What do wesee ? Type III (e beams) Wind/WAVES Type II (shockwave) III II shock e beam Nançay DA trapped e Kerdraon, Pick, Hoang, Wang, Haggerty 2010 ApJ 715, 468 Type IV (trapped e) ARTEMIS Nançay RH Frequency [MHz] IV Solar Radio Monitoring at Nançay Time (altitude)
2007 May 19: SEP event (STEREO) Whydoesthispoorlyconnectedsolaractivity(EUV: W05°) emitSEPsdetectedatEarth (Parker spiral W38°) ? Radio imaging (NRH): because the energeticelectrons (particles in general ?) are releasedwellwestward of the parent AR (shock and open flux tube geometry) ! Radio monitoring of the eruptive Sun What do wesee ? Type III (e beams) Wind/WAVES Type II (shockwave) Nançay DA Kerdraon, Pick, Hoang, Wang, Haggerty 2010 ApJ 715, 468 Type II Flaring AR ARTEMIS Nançay RH Type III STEREO + NRH Solar Radio Monitoring at Nançay
Solar-dedicated radio instrumentationNançay Observatory space Spectral identification of mapped sources • 2 historical instruments: • Radioheliograph (NRH; 150-450 MHz;onlysolar-dedicated imager atdm-m-) • DecametreArray (NDA; 20-70 MHz; unparalleledsensitivity and data quality; new digital receiver) • New spectrograph: ORFEES, completesspectrographiccoverage to 130-1000 MHz, including NRH frequencies (since 2012; coop. French Air Force) • New extension of NDA to 5 MHz: continuouscoverage to space-basedobserva-tions (Wind/WAVES, STEREO/SWAVES; since 2012) Nançay Solar Radio Monitoring at Nançay
Solar-dedicated radio instrumentationDistribution of Nançay data • French solar monitoring data: BASS2000 (http://bass2000.obspm.fr/) • SEPServerproject: Particle and EM data for SEP events (server.sepserver.eu) • Release of SEPServerthisafternoon, splinter meeting 17:15-18:45, Scala 3 ! • Radio-dedicateddatabase, in relation with STEREO/SECCHI (http://secchirh.obspm.fr/): • Spectrographic data Nançay, ARTEMIS (Greece), Wind/WAVES, STEREO/WAVES) • NRH overviewmovies • Underway to 24 h coverage in radio spectrography (Kunming, Culgoora, …) Solar Radio Monitoring at Nançay
Solar Radio Monitoring at Nançay Observatory Summary & conclusion • Radio observations of solareruptiveactivity trace potentiallygeo-effective dynamicalphenomena in the corona: escapingenergeticparticlebeams, shockwaves, CMEs (on the disk or at the limb). • Spectrographic data are availablefromseveral stations in Europe and worldwide (cf. CESRA websitehttp://lesia.obspm.fr/cesra/). • Somecanbedelivered 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 Rabove the photosphere. • Data provision for research(http://secchirh.obspm.fr/) and spaceweather applications (FEDOME spaceweatherdemonstrator, French Air Force). • Data available for future common services in Europe (cf. Spa. Sit. Aw. questionnaire) Solar Radio Monitoring at Nançay