Prominence-Corona Transition Region

1. Prominence-Corona Transition Region T. Kucera, NASA/GSFC ISSI Prominence Cavity Team Jan. 2009

2. Outline • Basic structure of the TR • What it looks like in the EUV • Prominence Motions - Models and Observations • ISSI Prominence Group Topics

3. What is the PCTR? Material between the bulk of the prominence material at T<104 K and the corona at T>106 K. B

4. Corona PCTR Prominence PCTR Corona What is the PCTR?

5. What is the PCTR?

6. What is the PCTR?

7. What is the PCTR?

8. Other TR Temperature Radiation

9. What does it actually look like?

10. Prominences at 304 Å 304 Å STEREO/SECCHI/EUVI 304 Å SOHO/EIT Contributions: He II collisionally excited (50,000-90,000 K) He II scattered (~104 K) (See Labrosse et al.) Lyman absorption (~104 K) Si XI (~106 K)

12. SOHO/CDS Chiuderi-Drago & Landi 2002

13. Coronal Emission? prominence associated jet TRACE Chae 2003 Not always. These transient bright features at 171 and 195 Å probably around 250,000 K. Erupting prominence, EIT 195 Å Ciaravella et al. 2000

14. TRACE 171(?) A

15. Differential Emission Measures • DEMs assume • Ionization equilibrium • Optically thin plasma Cirigliano et al. 2004 SOHO/SUMER and CDS

16. Karpen et al. 2008

17. Prominence Motions Prominences are dynamic! Quiescent prominences in H show steady flows, including counter-streaming, up to 20 km/s, and sometimes show faster motions. Prominences observed in EUV and UV often show faster motions (30-70 km/s)

18. Prominence Motions Study prominence motions at different temperatures to understand their properties and how they are related. Goal: to test theories of prominence formation (which tie into theories of magnetic structure).

19. Rising Magnetic Field Priest, van Ballegooijen, Mackay, 1996

20. Reconnection driven flows Wang, 1999

21. Chromospheric Heating/Siphon Flow Models Karpen et al.

22. Studies of Motions in Prominences - Results Many motions in the EUV seem to be pretty fast Some seem to have detectable H components. Are there EUV components to slower H motions? Its hard to tell, but this may be a resolution problem. In general DEMs of motions look rather like DEMs of prominences of a whole. One difference is the extent to which you can see >300,000 K material in the structure.

23. TRACE Ly and 1600 Å bands, May 26, 2000

24. SVST H Integrated Intensity and Doppler, May 26, 2000

25. Activated Prominence and Cool Loop Apr. 17, 2003 Kucera & Landi 2006

26. Prominence between active regions Apr. 29, 2004

27. Quiet and Activated Prominence Apr. 30 -May 1, 2004

28. DEMs of Moving Prominence Features • Different from others Promience DEMs because • Made using as small a piece of a moving feature as possible (in time and space) • When possible “background” has been estimated or subtracted • Calculated with using method of Landi & Landini 1997

29. Sample DEMs of Prominence Motions

30. Loop Differential Emission Measures Kucera & Landi 2006

31. Many motions in the EUV seem to be pretty fast Some seem to have detectable H components. Are there EUV components to slower H motions? Its hard to tell, but this may be a resolution problem. In general DEMs of moving features look rather like DEMs of prominences of a whole. One difference is the extent to which you can see >300,000 K material in the structure.

32. Plans & the Future • Can Dynamic Equilibrium Model simulate the short times scale DEMs? • SDO might be able to help understanding of the “high temperature” TR. Does this have any connection to very high temperature emission associated w/ prominences (“Chewy Nougat”)?

33. ISSI Prominence Group - Some topics • Prominence Radiative Transfer Observations & Modeling- Lyman Absorption, He lines • PCTR related observations and diagnostics • Flows • Oscillations • Prominence magnetic field, its formations and relationship to the cavity field (Aad)