EDP Sciences
Free Access
Issue
A&A
Volume 555, July 2013
Article Number A47
Number of page(s) 20
Section The Sun
DOI https://doi.org/10.1051/0004-6361/201220810
Published online 01 July 2013

Online material

Appendix B: Effective areas and long-term correction

In what follows, we provide some IDL commands to obtain the effective areas and the long-term correction within SolarSoft.

gdz_sw=[165, 171, 174.5, 177.2, 178.1, 180.4, 182.2, $ 184.5, 185.2, 186.9, 188.3, 190, $ 192.4, 192.8, 193.5, 194.7, 195.1, $ 196.6, 197.4, 200, 201.1, 202., $ 202.7, 204.9, 208., 209.9, 211.3] gdz_eff_sw=$ [0.000174973/1.5, 0.000255772/1.5,0.00158207/1.5, $ 0.00476608/1.55, 0.00705735/1.5, 0.0168637/1.45, $ 0.0316499/1.4, 0.0647319/1.35, 0.0779082/1.35, $ 0.115240/1.4, 0.150199/1.45, 0.194897/1.25, $ 0.255993/1.13, 0.264945/1.1, 0.279607/1.05, $ 0.298884/1.02, 0.302737*1., 0.301859/1.05, $ 0.287675/1.15, 0.174608*1.05, 0.119586/1.0, $ 0.0838537 /1., 0.0635698/1., 0.0332376/1.0 , $ 0.0189209/1., 0.0133581/1., 0.0105513/1.] gdz_lw=[245., 252., 255, 257., 259, $ 263. , 265., 268., 270., $ 272. , 274. , 277., 281., 286., 292] gdz_eff_lw=$ [0.022673*0.8, 0.03908*0.75, 0.05065*0.78, $ 0.0588*0.8, 0.06738*0.85, 0.0861*0.9, $ 0.09551*0.95, 0.106984*1.0, 0.110764*1.02, $ 0.10944*1.03, 0.1026*1.03, 0.084775*0.9, $ 0.05718*0.87, 0.0333*0.85, 0.01679*0.85]/1.1 ;the effective area at a SW wavelength(Angstroms) ;w1 is obtained as ;eff=interpol(gdz_eff_sw , gdz_sw, w1),/spline) ;the effective area at a LW wavelength(Angstroms) ;w2 is obtained as ;eff= interpol(gdz_eff_lw , gdz_lw, w2),/spline) ;-------------------------------------------------- Xtime_ref=ANYTIM2TAI('22-Sept-2006 21:36:00.000') coeff1=[1.0326230, -5.2495791e-09, 1.2055185e-17] ; date is any observation time. Xtime=ANYTIM2TAI(date) ; degr gives the degradation degr=poly(Xtime - Xtime_ref, coeff1) We note that this correction cannot be extrapolated to dates later than September 2012.

Appendix C: The Si vii vs. Fe viii problem

We have calculated the contribution functions G(T) of a selection of TR lines observed by Hinode/EIS, using CHIANTI v.7.1 data (Landi et al. 2012), in particular the new ion abundances (in ionisation equilibrium). They are shown in Fig. C.1 (top). Any small differences in the contribution functions of two lines in the transition region, where there is a steep variation in temperature, can have a large effect (see, for example, the large effects on active region loops in Del Zanna 2003).

To estimate the effects that a steep variation in temperature can have, we have taken a QS DEM obtained from the on-disk EIS observations of 2006 Dec 23, and folded it with the G(T) of a few main EIS lines, as an example. They are shown in Fig. C.1 (bottom). It is clear that the emission in the Fe viii and Si vii has two main components, one coronal (1 MK) and one in the lower transition region. It is also clear that the TR component of Fe viii should have a similar response to that of Mg vi, and not Si vii. It is fair to say, however, that for both Fe viii and Si vii a significant contribution is predicted to originate from the coronal component. This is of course assuming that a continuous distribution of plasma between TR temperatures and the corona exists. The TR Si vii component accounts for almost 30% of the intensity of the line in the log T[K] = 5.2–5.9 range, while the Fe viii TR component accounts for over 40%; Mg vi is clearly a pure TR line.

thumbnail Fig. C.1

Top: contribution functions G(T) of a selection of TR lines observed by Hinode/EIS, using CHIANTI v.7.1 data. Bottom: the same G(T) values multiplied for a QS DEM. We note that the G(T) × DEM(T) of Mg vi was increased by a factor of two.

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