1. Imaging The Active Region TR With The CDS Wide SlitMike MarshCentre for Astrophysics, University of Central Lancashire, Preston, UK

2. The Wide Slit Mg IX 368 Å He I 584 Å O V 629 Å • 90˝× 240˝ FOV • 26s cadence • Produces intensity images (not rastered) in He I, O V & Mg IX • But no spectral data

3. Wide Slit Calibration Mg IX uncalibrated Mg IX calibrated

4. AR 10570 EIT 171 Å TRACE WL TRACE 1600 Å TRACE 171 Å

5. AR 10570

6. TRACE 1600 Å TRACE 1600 +171 Å TRACE 1600 +O V

7. Composite Movie TRACE 1600 Å O V TRACE 171 Å

8. Composite Movie O VTRACE 171 Å

9. Rastered data Rastered data gains line profile data, but loses time variability information

10. MDI WL + O V + 171 TRACE 171 + O V TRACE 171

11. Fourier power maps Power significant to 95% 3 min band (4.7 – 6.6 mHz) (150 – 210 s) 3-min umbral oscillations Beckers & Tallant (1969), Gurman (1982), Fludra (2001), Brynildsen (2002)

12. 3 min He I time series • He I oscillation amplitude ~2% • FFT has 2 dominant periods ~ (6.1 & 7.1) mHz (140 & 160) Seconds

13. 3 min O V time series • O V oscillation amplitude ~4% • FFT has 2 dominant periods ~ (5.9 & 7.3) mHz (140 & 170) Seconds

14. AR 10570 with TRACE ~80 kms-1 projected velocity cf. De Moortel et al. (2002) Robbrecht et al. (2001)

15. 3 min TRACE 171 time series • TRACE oscillation amplitude ~3% • FFT has 3 dominant periods ~ (3, 5.9 & 7.3) mHz (330, 140 & 170) Seconds

16. Conclusions • Chromospheric/TR Acoustic Waves (Brynildsen, 2004) • Waves propagate through chromosphere, TR and into the corona • 3 min oscillations above sunspot umbra in the Chromosphere & TR where the umbral magnetic field is vertical • Oscillations observed as 3 min propagations at TRACE temperatures where the field is more inclined.

17. Acoustic Energy Flux • Assuming acoustic waves with velocity and pressure perturbations V' and P' • The energy flux of the wave ε is given by: Assuming: • Optically thin emission → • Ideal gas • Complete ionisation of the plasma & Relative abundances X=0.9 Y=0.1 → The energy flux of the wave is given by:

18. Acoustic Energy Flux O V Doyle (2003) derive Ne in sunspot plumes using O V diagnostic TRACE 171 Del Zanna (2003) derive Ne in the footpoints of quiescent coronal loops He I Estimated Log Ne=11cm-3 for active regions

19. Conclusion • Acoustic waves propagate through chromosphere, TR and into the corona • Acoustic waves are insufficient to heat active regions • Technique may be used as a seismological tool to determine plasma properties ρ, T,… • If ε constant through the atmosphere; may allow derivation of Ne at He I temperatures • Need active region Ne measurement at He I temperatures