1. 1 Wei Liu, Tongjiang Wang, Brian Dennis, & Gordon Holman NASA Goddard Space Flight Center Evidence of Magnetic Reconnection & Existence of Current Sheet in a Partially Occulted Flare Following a Prominence Eruption Thanks to Ryan Milligan, Richard Schwartz, Yang Su, Kim Tolbert, Andy Gopie

2. 2 GOES C-7.7 Krucker’s WIND/WAVES No electron events @ 1 AU

3. 3 RHESSI X-ray Spectrogram (front segments)

4. 4 Energy by time mosaic – general trend keV 25-50 17-25 12-17 9-12 6-9 3-6 Time in 1-minute intervals Impulsive phase peak (footpoints occulted by solar limb)

5. 5 Preheating : thermal Impulsive rise: thermal+nonthermal Impulsive peak: thermal+nonthermal Decay phase: thermal

6. 6 TRACE Lyman alpha Prominence eruption also seen in ISOON H-alpha images (not shown)

7. 7 EIT running difference erupting prominence

8. 8 RHESSI contours on TRACE 195 (preheating phase, note helical flux rope in lower panels)

9. 9 RHESSI on TRACE (cont’d, impulsive rise, peak, decay phases; note cusp and current-sheet like structure after prominence eruption, & multiple X-ray sources)

10. 10 RHESSI 8-15 keV @impulsive peak (15:47– 15:48), on TRACE 195 (15:52, 4 minutes later) GOES-12 SXI, 15:57

11. 11 Reconnection site Source morphology at different energies: sources shift closer at higher energies (more pronounced for the lower source)

12. 12 20 30 40 Source position at different energies (cont’d)

13. 13 Imaging spectroscopy @ impulsive peak Lower coronal source: T=19 MK, EM=4.9x10 47 cm -3 γ=6.4 Upper coronal sources: T=24 MK, EM=1.5x10 47 cm -3 γ=8.7

14. 14 Summary & Discussion (1) Slow (localized) reconnection & heating developed in preheating phase, associated with activation of the prominence before its eventual eruption: * Twists – existing prior to eruption or formed via reconnection during activation? * Helicity transferred into flux rope while reconnection occurs? (2) Current sheet or jet seen in TRACE 195? * X-ray morphology suggests reconnection site in a vertical current sheet; * Lower coronal source: strong nonthermal + cooler thermal (19 MK), upper coronal sources: weak nonthermal + hotter thermal (24 MK); * T~20+ MK at peak time, much higher than Yohkoh/SXT jets (4–8 MK); (3) Prominence eruption results in vertical current sheet; consequent fast reconnection leads to impulsive phase and rapid energy release.