1. Coronal Loops Workshop 6, La Roche-en-Ardenne, Belgium, 25-27 Jun 2013 Density of active region outflows derived from Fe XIV 264/274 Naomasa KITAGAWA & Takaaki YOKOYAMA The University of Tokyo, Japan

2. Coronal Loops Workshop 6, La Roche-en-Ardenne, Belgium, 25-27 Jun 2013 Discovery of AR outflows In dark location v=50-150 km s -1 Persistent Emanated from ‘open’ region Fe XII intensity Doppler vel.Width (Doschek 2008)

3. Coronal Loops Workshop 6, La Roche-en-Ardenne, Belgium, 25-27 Jun 2013 Upflows from footpoints of active region loops Line profile = EBW + Main component Intensity V NT (Hara et al. 2008) EBW

4. Coronal Loops Workshop 6, La Roche-en-Ardenne, Belgium, 25-27 Jun 2013 R-B asymmetry Ubiquitous EBWs in footpoint regions (De Pontieu et al. 2009) Spatial correspondence with propagating disturbances in fan loops (Tian et al. 2011) (Tian et al. 2011) (De Pontieu et al. 2009)

5. Coronal Loops Workshop 6, La Roche-en-Ardenne, Belgium, 25-27 Jun 2013 DEM of AR outflows FIP bias of outflows: 3–5 –Coronal origin i.e. not the photospheric Total emission EBW Asymmetries of the emission lines peak in the coronal temperature (around Fe XII). Fe VIII Si X S X Fe XIIFe XIIIFe XV (Brooks & Warren 2012)

6. Coronal Loops Workshop 6, La Roche-en-Ardenne, Belgium, 25-27 Jun 2013 Motivation Properties revealed so far –Persistency –Location: AR edge Boundary of close & open field? –Doppler velocity: 50-150 km s -1 –DEM: close to AR What should we know about AR outflows? –Driving mechanism –Source (in terms of height) Density ( n e ) of AR outflows ITSELF is one of the key clues to approach the nature of them. cf. ) Density of outflow regions –7x10 8 cm -3 (Doschek et al. 2008, Fe XII total emission) –10 8.4-8.9 cm -3 (Brooks & Warren 2012, Fe XIII total emission)

7. Coronal Loops Workshop 6, La Roche-en-Ardenne, Belgium, 25-27 Jun 2013 Simultaneous fitting for Fe XIV 264/274 Wavelength calibration –Each component in Fe XIV 264/274 must have the same Doppler velocity because the emission comes from Fe XIV. Double-Gaussian fitting EBW Main ⇒ Histogram for l 274 / l 264

8. Coronal Loops Workshop 6, La Roche-en-Ardenne, Belgium, 25-27 Jun 2013 Density diagnostics of AR outflows CHIANTI ver.7 (Dere et al. 1997, Landi et al. 2013) Outflow region Main componentEBW Density map for each component

9. Coronal Loops Workshop 6, La Roche-en-Ardenne, Belgium, 25-27 Jun 2013 Density: EBW vs. Main component EBW (outflows): ～ 10 8.7 cm -3 Main: ～ 10 9.2 cm -3 EBW (outflows) Main component Main component EBW EBWs (outflows) are more tenuous than the main component.

10. Coronal Loops Workshop 6, La Roche-en-Ardenne, Belgium, 25-27 Jun 2013 Column depth of AR outflows EBW: 10 8.2±0.6 cm Main: 10 7.7±0.2 cm Although emission of AR outflows is weak, they dominate in terms of the volume. (h* for two components were calculated separately.)

11. Coronal Loops Workshop 6, La Roche-en-Ardenne, Belgium, 25-27 Jun 2013 Density diagnostics without fitting Derivation of N e from I 264 /I 274 at each spectral bin....... spectrum “ l -N e diagram” Wavelength scale is adjusted. △ : solution : diagram

12. Coronal Loops Workshop 6, La Roche-en-Ardenne, Belgium, 25-27 Jun 2013 l -N e diagram in AR10978 AR core –log N e ( l ) ≃ 9.5 Outflow region –Dip around 274.1Å (v ～ 100 km s -1 ) AR coreOutflow region It is confirmed that outflows are more tenuous than the dominant, rest component.

13. Coronal Loops Workshop 6, La Roche-en-Ardenne, Belgium, 25-27 Jun 2013 Discussion (1) n outflow < n Main –The outflows observed here were not likely produced as a result of impulsive heating (e.g., nanoflare). However, this is not decisive because we do not know whether the two components in emission lines come from the same magnetic structure or not. (2) h * outflow > h * Main –The volume of the outflows is larger than that of the main component, contrary to their weakness in emission line profiles. (3) Doppler velocities indicate blueshift for log T≥5.8. –Different from fan loops Driving mechanism in somewhat steady manner is required.

14. Coronal Loops Workshop 6, La Roche-en-Ardenne, Belgium, 25-27 Jun 2013 Summary of results EIS observation on AR10978 Density measurement –Main: ≃ 10 9.2 cm -3 –Outflows: ≃ 10 8.7 cm -3 Column depth –Main: 10 7.7±0.2 cm –Outflows: 10 8.2±0.6 cm Verification by “ l -N e diagram” Histogram for N e Outflows Main

15. Coronal Loops Workshop 6, La Roche-en-Ardenne, Belgium, 25-27 Jun 2013 End