The Relationship Between CMEs and Post-eruption Arcades

1. The Relationship Between CMEs and Post-eruption Arcades Peter T. Gallagher, Chia-Hsien Lin, Claire Raftery, Ryan O. Milligan

3. Recap of CME Morphology • “Typical” event consists of 3 components: • Ejection of coronal magnetic field and mass • Ejection of filament/prominence field and mass • Heating of > 10MK flare coronal loops and acceleration of flare particles (Krucker) • Strength of each component can vary between events, but all are present to some degree • How are they related?

4. Non-Dipole Coronal Topology • Field of two dipoles – axi-symmetric • Large global at Sun center, weaker near surface • Must have 4-flux system with separatrix bdys, and null

5. Non-eruption • Bipolar (one polarity inversion line) initial magnetic field • Filament-field formation by shearing and reconnection • See pronounced expansion & kinking – but no eruption Underlying physics: • Corona has no lid • Magnetic field lines can stretch indefinitely without breaking • Free to open slowly in response to photospheric stress and gas pressure (rather than erupt as CME) • Slow opening (not associated with filament channels) observed to occur continuously in large-scale corona (from,DeVore et al, 2005; Aulanier et al, 2005)

6. Breakout Model • 2D multi-polar initially potential field • Create filament channel by simple footpoint motions • Outward expansion drives breakout reconnection in corona

7. Breakout Model • Breakout reconnection allows for explosive eruption • Flare current sheet, flare reconnection, and twisted flux rope all consequences of ejection • CME with no flare possible for slow eruptions

8. Ideal Instability

10. Open CME questions • What are the forces governing the propagation and expansion of CMEs? • Is there a relationship between CME kinematics and post-flare loop kinematics?

11. CME Kinematics • Kinematics are governed by force balance equation:

12. Standard Flare Model

13. CME Models • All models are based on the principle that CMEs are driven by the sudden release of the free magnetic energy stored in pre-eruptive coronal magnetic fields. • Resistive MHD models: where magnetic reconnection in a current sheet plays an important role in triggering the CME onset and in sustaining the eruption. • Ideal resistive hybrid: where eruption is triggered by an ideal loss of equilibrium of the magnetic field but that subsequent formation of a current sheet and magnetic reconnection is crucial for sustaining the eruption and allowing a magnetic flux rope to escape. • Non-force free models: the weight of the prominence mass plays a important role in building up the magnetic energy to exceed that of the open-field limit, and that a sudden drop of the prominence weight triggers the eruption.

14. Overview of 17-Dec-2006 Event

15. CME Kinematics

16. Post-flare arcade kinematics

17. CME and Arcade Kinematics

19. 24-hours

21. ~

22. Comparison of events

24. A comparable event: 21-Apr-2002

25. Conclusions • Is there a relationship