Solar Physics Division 2013 report Data reduction and interpretation RESIK RESIK was a unique Bragg crystal spectrometer operating on one from the two previous missions of the Russian CORONAS program. RESIK was launched on CORONAS-F satellite on 31 July 2001.The instrument took measurements close to the maximum of 23rd solar activity. The instrument recorded ~1. 8 mln. high quality spectra in the spectral range 3.3-6.1 Å. In the spectra, several prominent X-ray emission lines are seen formed in active regions and flares. In 2013, further analyses of these spectra have been performed. The main results obtained are the following: The active binary stars σ Gem and HR1099 X-ray spectra obtained from the Chandra High Energy Transmission Grating Spectrometer have been compared with the solar flare spectra obtained with the RESIK instrument at similar resolution in an overlapping bandpass. We show the spectra and models in the short wavelength region where HETG and RESIK spectra overlap. Flux-corrected spectra are in black, and the red is the model convolved by the instrumental resolution. Below each, in blue, are residuals. The top panel shows σ Gem; the middle is HR 1099; the bottom is the rise phase of the solar flare on 2002 December 26 (maximum at 06:30 UT). (Huenemorder, Phillips, Sylwester & Sylwester, The Astrophysical Journal, 768:135 (15pp), 2013 May 10). The primary goal of this work was to compare low and high FIP elemental abundances in the Sun and stars. We have determined new elemental abundances. For the lowest FIP species—particularly K and Na, the abundances in σ Gem is similar to that in the solar corona, other low-FIP elements (Na, Al, Ca, Mg, Fe, and Si) are strongly depleted, only becoming near or above solar for the high FIP elements N, Ar, and Ne. Even the stellar S abundance (considered high-FIP) has a very low relative abundance. In another study RESIK fluxes of the Si XIV Ly-β line (5.217 Å) and the Si XIII 1s2 – 1s3p line (5.688 Å) for 21 flares have been analyzed to obtain the silicon abundance relative to hydrogen. The emitting plasma for each spectrum was assumed to be characterized by a single temperature and emission measure given by the ratio of emission in the two channels of GOES. Upper panel: Spectra for RESIK Channels 3 and 4 for all 1822 spectra analyzed in this work, stacked in order of TGOES increasing upwards, with the scale shown on the left. Lower panel: Five RESIK Channels 3 and 4 spectra averaged over 2MK intervals, with the average temperature TGOES shown in each case. The Si XIV Ly-β line at 5.217 Å has increasing intensity relative to the Si XIII 1s2 −1s3p line at 5.688 Å for increasing TGOES, while the Si XIII line predominates in Channel 4 spectra at lower temperatures. The silicon abundance was determined to be A(Si) = 7.93 ± .21 (Si XIV) and 7.89 ± .13 (Si XIII) on a logarithmic scale with H = 12. These values, which vary by only very small amounts from flare to flare and times within flares, are 2.6 ± 1.3 and 2.4 ± 0.7 times the photospheric abundance, and are about a factor of three higher than RESIK measurements during a period of very low activity. There is a suggestion that the Si/S abundance ratio increases from active regions to flares. (B. Sylwester · K.J.H. Phillips · J. Sylwester · A. Kępa, Solar Phys. 283:453–461) A new analysis method AbuOpt for determination of time/temperature dependent composition and differential emission measure structure of flaring plasmas have been developed and used for the analysis of selected flare (SOL2002-11-14T22:26). The analysis method starts by finding an abundance set that is consistent with the observed spectra, then solves for the differential emission measure shape using a maximum-likelihood routine (the Withbroe– Sylwester method). The abundance optimization leads to revised abundances of silicon and sulfur in the analyzed flare plasmas: A(S) = 6.94 0.06 and A(Si) = 7.56 0.08 (on a logarithmic scale A(H) = 12). (Left :) Contour plot of the differential emission measure during the SOL2002-11-14T22:26 flare, darker colors indicating greater emission measure. The horizontal scale is the logarithm of temperature, and the time increases upwards, measured from 22:14:41 UT. Horizontal dotted lines define the time intervals a, g, i, l, and q and the smooth curve running from top to bottom is the temperature derived from the ratio of the two GOES channels on an isothermal assumption. (Right:) Emission measure distributions for the intervals indicated in the left plot, derived from the Withbroe–Sylwester routine. Vertical error bars indicate uncertainties. A cooler (temperature 4 - 5 MK) component is present over the entire time interval shown, with hotter component (~18 MK) at the peak of the GOES light curve. During the flare’s maximum phase, the DEM analysis shows the X-ray-emitting plasma to have a basically two-temperature component, with the cooler plasma at approximately constant temperature (4–5 MK) and hotter plasma at ~18 MK. The cooler plasma is present before, during, and after the flare maximum. (B. Sylwester, J. Sylwester, K.J.H. Phillips, A. Kępa, T. Mrozek, ApJ, under review) SphinX SphinX soft X-ray spectrophotometer successfully operated aboard the Russian CORONAS-Photon satellite between February and December 2009. The instrument collected ~2 mln. spectra covering a period of very low solar activity, the lowest since approximately 100 years. No other X-ray instrument was capable of taking the X-ray spectra at such low activity and therefore the SphinX measurements are unique in this respect. The CORONAS -Photon, third spacecraft of this series, has been launched on 30 January 2009. Over the year 2013, comparison of SphinX measurements with other measurements making similar X-ray measurements have been performed. In particular the MESSENGER data from SAX solar monitor has been used and fluencies compared in similar energy bands. The comparison of soft X-ray lightcurves as recorded by SphinX D1 detector (blue line) and two channels of MESSENGER SAX (in black and gray). For the period indicated, centered on 19- September 2009, the Messenger spacecraft looked at the same part of the solar corona as SphinX from Earth orbit. A very good correspondence has been observed (as seen on the above plot). This indicates that the databases of SphinX and SAX complement each other, however the SphinX sensitivity for D1 detector is at least order of magnitude better than SAX. Quantitative analysis of common data set is in progress (Anna Kępa). Solar corona during 2009 activity minimum Common analysis of the SphinX spectra and Hinode/XRT intensities for the most in-active corona observed allows to distinguish four clear features in the temperature distribution of emission (DEM): colder emission below 1 MK (log T ≈ 5.9), main maximum at ~1 MK (for log T in the range 5.9-6.1), a second maximum or enhancement at ~1.6 MK (for log T in the range 6.1- 6.4) and a hotter emission with T>2.5 (log T above 6.4). Using XRT temperature maps as obtained applying image-ratio technique allows to unveil the spatial arrangement of these different plasma temperature components in projection. Example of derived temperature maps is presented in the Figure below for 2009 February 21 0604 UT, the period of lowermost global solar soft X-ray flux yet measured. An example of temperature map obtained from Hinode/XRT data on 2009 Feb 21 06:04 UT. Black, blue, yellow, and red colors correspond to log(T) = 5.0 > 5.9 > 6.1 >6.4 ranges respectively as shown in the inset. The characteristic white network corresponds mainly to the CCD pixels where the contamination effects were pronounced. These pixels were not used for temperature mapping. The colors represented plasmas at indicated temperatures. We can see that the colder emission corresponds to regions of coronal holes and above towards outer corona. Blue color corresponding to T in the range 0.8 – 1.3 MK i.e. close to “an average” quiet corona temperature is distributed over most of the disk. The yellow areas corresponding to somewhat hotter emission on DEM distribution with T in the range 1.3 – 2.5 MK constitutes left-overs of the “active corona” i.e. small active regions and the bright points. This hotter emission occupies also regions of inner corona close above the limb. The red color areas represent the quiet corona hottest emission where T > 2.5 MK. No red colors are seen within active regions and/or bright points due to saturation of respective XRT pixels. No hottest emission is seen on the disk, but it overwhelms the outer corona due to line-of-sight integration effects. These results have never been obtained before and respective publication is under preparation (Marek Siarkowski et al.). They were discussed during the XVI Consultations on Solar Physics (22-25 May 2013) in Wrocław, Poland . Theoretical Modeling We (Sylwester Kołomanski, Tomek Mrozek and Barbara & Janusz Sylwester) continued modelling efforts of the response of solar atmosphere to flare energy release occurring in the corona confined within a “rigid” magnetic environment of coronal loop. For the first time, we modelled the evolution of plasma along the loop throughout entire event, in the flare scenario considered covering approximately 1.5 day. Such a long modelling exercise was possible thanks to the access to supercomputers at the Wroclaw Academic Supercomputer Centre. For the first time we can study the late phase of flare evolution showing the “recovery” of flaring plasma to initial condition, before the flare heating initiation. On the diagnostic diagram shown, this decay-phase variability strictly follows so-called quasi-steady-stay cooling. This type of evolution is characteristic for the case of the heating operating quite long into the decay of the event. Example of time variability of physical conditions as modelled using the Palermo-Harvard HD code for a loop of semi-length 50 Mm. Time dependence of the plasma temperature T, density N and pressure P are plotted in the three upper-left diagrams in color, representing the time elapsed from switch-on of flare heating at t=500s. The fourth diagram (lower-right) represents so-called diagnostic diagram.