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 15 4 14 2 ABSTRUCT 3 INTRODUCTION 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) 1 EIT wave coronal wave 4 INTRODUCTION flare-related phenomena seen in the chromosphere (H ) (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). 1 Moreton wave 5 Uchida model (1968) shock front Moreton wave ?? wave, coronal counterpart of Moreton wave flare site solar disk 6 INTRODUCTION Warmuth et al., 2001 Moreton wave and coronal wave are cospatial, and decelerate. 1 H Moreton wave & EIT coronal wave Eto et al., 2002 Moreton wave differs physically from coronal wave. speed and location 7 INTRODUCTION 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. 1 CME & EIT coronal wave 8 INTRODUCTION 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. 1 9 INSTURUMENTATION TRACE cadence : 1~2 sec wavelength 195 (half-resolution) 171 (full-resolution) 1216 (half-resolution) SOHO/EIT wavelength 195 wave and dimming 304 filaments SOHO/CDS raster time : 5 minutes field of view : 102 240 7 wave bands 2 10 OBSERVATIONS AND DATA ANALYSIS /06/13 15:00UT AR 8237 C2.9 EIT 195 image TRACE CDS 11 OBSERVATIONS AND DATA ANALYSIS Coronal Wave TRACE 195 percentage difference image : (image 15:25:52 image) / 15:25:52 image CDS 12 OBSERVATIONS AND DATA ANALYSIS Coronal Wave percentage difference image : (image 15:25:52 image) / 15:25:52 image 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 13 OBSERVATIONS AND DATA ANALYSIS Expelled Material O V ( ) vel2 vel1 2 components vel1: either nearly stationary or relatively 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 Expelled Material O V ( ) transition region Log T = 5.4 15 OBSERVATIONS AND DATA ANALYSIS vel2 Mg X : corona O V : transition region He I : cool cover a wide temperature range propagation velocity : 150 ~ 270 km/s Expelled Material blueshift 300 km/s 16 OBSERVATIONS AND DATA ANALYSIS Expelled Material blueshifted O V & filament Blueshifted O 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 Expelled Material blueshifted O V & filament val1 stay val2 200 km/s filament 18 OBSERVATIONS AND DATA ANALYSIS Expelled Material blueshifted O V & filament 19 DISCUSSION 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. 4 coronal wave observed with TRACE 20 DISCUSSION 4 coronal wave weak wave : line-of-sight velocity : less than about 10 km/s dimming result from CME material being expelled away from the SUN (Harra & Sterling, 2001). coronal wave observed with CDS 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 Chens simulation & observation 23 Moreton wave timing of ejected filament material 24 MHD shock theory (Priest, 1982) BEHINDAHEAD Shock front Using Eq. (1)-(7), the quantities ahead of the shock (I X1,T 1,B 1, 1,v 1 ) determine those behind (I X2,T 2,B 2, 2,v 2 ). I X1 T 1 B 1 1 v 1 I X2 T 2 B 2 2 v 2 I X1 T 1 B 1 1 v 1 I X2 T 2 B 2 2 v 2 Narukages estimation of line-of-sight velocity 25 Prediction From my analysis, we can estimate the coronal plasma velocity just behind the Moreton wave (fast-mode MHD shock), v 1 -v 2, 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. BEHINDAHEAD Narukages estimation of line-of-sight velocity 26 DISCUSSION 4 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 Ejected filament-like material 27 DISCUSSION 4 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 in the future END Thank you very much for your attention.