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L OUISE K. HARRA AND A LPHONSE C. STERLING ApJ 2003, 587, 429 – 438

太陽雑誌会 発表日時 ： 平成 15 年 4 月 14 日. IMAGING AND SPECTOROPIC INVESTIGATIONS OF A SOLAR CORONAL WAVE: PROPERTIES OF THE WAVE FRONT AND ASSOCIATED ERUPTING MATERIAL. L OUISE K. HARRA AND A LPHONSE C. STERLING ApJ 2003, 587, 429 – 438. ABSTRUCT. INTRODUCTION. 1. EIT wave – coronal wave.

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L OUISE K. HARRA AND A LPHONSE C. STERLING ApJ 2003, 587, 429 – 438

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  1. 太陽雑誌会 発表日時 ： 平成 15 年 4 月 14 日 IMAGING AND SPECTOROPIC INVESTIGATIONS OF A SOLAR CORONAL WAVE: PROPERTIES OF THE WAVE FRONT AND ASSOCIATED ERUPTING MATERIAL LOUISE K. HARRAANDALPHONSE C. STERLING ApJ 2003, 587, 429 – 438

  2. ABSTRUCT

  3. INTRODUCTION 1 EIT wave – coronal wave • observed with SOHO/EIT. • appear as roughly circular propagating features. • appear as a bright front. • a few hundred km/s. • TRACE also observed (Wills-Davey & Thompson, 1999)

  4. INTRODUCTION 1 Moreton wave • flare-related phenomena seen in the chromosphere (Ha) (Moreton 1961). • propagate at a speed of about 1000 km/s. • identified as the footpoints of a fast-mode wave in the corona (Uchida 1968).

  5. Uchida model (1968) flare site shock front Moreton wave ?? wave,coronal counterpart of Moreton wave solar disk

  6. INTRODUCTION Warmuth et al., 2001 Moreton wave and coronal wave are cospatial, and decelerate. Eto et al., 2002 Moreton wave differs physically from coronal wave. – speed and location 1 Ha Moreton wave & EIT coronal wave

  7. INTRODUCTION 1 CME & EIT coronal wave • CME – Coronal Mass Ejection • filament material typically trailing behind a main CME front. • CME & EIT coronal wave • Sharp, well-defined coronal waves are always associated with flare and CMEs, and Moreton waves are frequently observed in these case.

  8. INTRODUCTION 1 • In this paper, we attempt to improve our understanding of coronal waves and their relation to eruptions by observing an event on the solar disk using EUV imaging and spectral observations.

  9. INSTURUMENTATION 2 • TRACE • cadence : 1~2 sec • wavelength • 195Å (half-resolution) • 171Å (full-resolution) • 1216Å (half-resolution) • SOHO/EIT • wavelength • 195 Å – wave and dimming • 304 Å – filaments • SOHO/CDS • raster time : 5 minutes • field of view : 102” × 240” • 7 wave bands

  10. OBSERVATIONS AND DATA ANALYSIS 3 1998/06/13 15:00UT AR 8237 C2.9 TRACE CDS EIT 195 image

  11. OBSERVATIONS AND DATA ANALYSIS 3 3.1. Coronal Wave – TRACE 195Å CDS percentage difference image : (image – 15:25:52 image) / 15:25:52 image

  12. OBSERVATIONS AND DATA ANALYSIS 3 3.1. Coronal Wave “bright wave” : 200 km/s “weak wave” : 500 km/s • “weak wave” • interacts with a set of loops (TRACE): loop oscillation • line-of-sight motion (CDS): no substantial line shifts less than 10 km/s percentage difference image : (image – 15:25:52 image) / 15:25:52 image

  13. OBSERVATIONS AND DATA ANALYSIS vel2 vel1 3 3.2. Expelled Material – O V (629.75Å) 2 components • vel1:either nearly stationaryorrelatively weakly blueshifted. • vel2:much more strongly blueshifted.

  14. OBSERVATIONS AND DATA ANALYSIS vel1 blueshift : 150 km/s velocity : stay observed in only O V vel2 blueshift : 350 km/s velocity : 200 km/s observed in other emission lines 3 3.2. Expelled Material – O V (629.75Å) transition region Log T = 5.4

  15. OBSERVATIONS AND DATA ANALYSIS 3 3.2. Expelled Material – blueshift 300 km/s vel2 • Mg X : corona • O V : transition region • He I : cool cover a wide temperature range • propagation velocity : 150 ~ 270 km/s

  16. OBSERVATIONS AND DATA ANALYSIS 3 3.2. Expelled Material – blueshifted O V & filament BlueshiftedO V = vel2 surge or filament-like feature,with a portion of the feature braking off from another (southern) portion that remains attached to the SUN. This braking up of the ejected feature could be responsible for the two velocity components, val1 and vel2.

  17. OBSERVATIONS AND DATA ANALYSIS 3 3.2. Expelled Material – blueshifted O V & filament val1stay val2200 km/s filament

  18. OBSERVATIONS AND DATA ANALYSIS 3 3.2. Expelled Material – blueshifted O V & filament

  19. DISCUSSION 4 coronal wave observed with TRACE • coronal wave consists of two features (or aspects) • bright wave :roughly circular wave front  break up • weak wave :appears to form from dispersion of the bright wave.

  20. DISCUSSION 4 coronal wave observed with CDS • coronal wave • weak wave : • line-of-sight velocity : less than about 10 km/s • dimmingresult from CME material being expelled away from the SUN (Harra & Sterling, 2001).

  21. DISCUSSION Uchida et al., 2001 :EIT coronal waves are due to secondary ling-wavelength first-mode waves that have a lower propagation velocity than Moreton wave. Chen et al., 2002 : Moreton wave :piston-driven shock EIT wave :the opening of the field lines associated with an erupting flux rope. 4 numerical simulation

  22. DISCUSSION line-of-sight velocity observation : > 10 km/s simulation : much faster timing of ejected filament material observation :several minutes after the passage of the coronal wave simulation :There can be a large set of overlying magnetic fields, which drive the coronal wave, above the filament.  consistent 4 Chen’s simulation & observation

  23. Moreton wave おまけ timing of ejected filament material

  24. MHD shock theory (Priest, 1982) おまけ Narukage’s estimation of line-of-sight velocity BEHIND AHEAD Shock front IX2 T2 B2 θ2 v2 IX2 T2 B2 θ2 v2 IX1 T1 B1 θ1 v1 IX1 T1 B1 θ1 v1 Using Eq. (1)-(7), the quantitiesahead of the shock (IX1,T1,B1,θ1,v1) determine those behind (IX2,T2,B2,θ2,v2).

  25. Prediction From my analysis, we can estimate the coronal plasma velocity just behind the Moreton wave (fast-mode MHD shock), v1-v2, to be about 100~200 km/s, which would be observed at 50~100 km/s along the line-of-sight with SOHO / CDS or Solar B / EIS. おまけ Narukage’s estimation of line-of-sight velocity BEHIND AHEAD

  26. DISCUSSION 4 Ejected filament-like material • observed ejection at cool (He I), transition region (O V), and coronal (Mg X) temperature. • cool filament material being ejected together with hotter surrounding material. • There are probably two physical parts. • < 300 km/s :violently thrown out from the SUN • 150 km/s :either leaves more slowly or end up not leaving the SUN

  27. DISCUSSION 4 in the future • The Solar-B satellite will have the potential to carry out this type of analysis more regularly. • EUV Imaging Spectrometer (EIS) • 2 km/s Doppler velocity resolution • FOV : 6’ x 8’ • spatial resolution : 1”

  28. END Thank you very much for your attention.

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