Observations of Solar X-ray Spectra by the DIOGENESS and RESIK Spectrometers Onboard the CORONAS-F Satellite

Abstract

The first scientific results of the analysis of the X-ray spectra of flares and active regions in the solar corona obtained by Polish-led spectrometers RESIK and DIOGENESS onboard the CORONAS-F satellite are presented. The instruments were designed and made in the Solar Physics Division of the Space Research Center of the Polish Academy of Sciences (SRC PAS, Wroclaw, Poland). The Institute of Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation (IZMIRAN, Russia) and the Astronomical Institute of the Czech Academy of Sciences also participated in designing the DIOGENESS spectrometer, while IZMIRAN (Russia), Mullard Space Science Laboratory (MSSL, Great Britain), Rutherford Appleton Laboratory (RAL, Great Britain), and Naval Research Laboratory (NRL, United States) contributed to the development of the RESIK spectrometer. In the paper, we give spectra obtained in a number of previously unstudied spectral ranges and a preliminary identification of new spectral lines. The results for the shifts of the X-ray spectral lines observed with the use of a so-called dopplerometer configuration are also presented. Methods for determining the abundances of the rare elements in the solar corona, including chlorine, potassium, and argon, are described.

Solar X-rays from Axions: Rest-Mass Dependent Signatures

“…Figure 1: Solar X-ray spectra: Quiet and Active Sun (reconstructed) [1]. The other directly measured spectra (RESIK, RHESSI) refer to a flare (red) [4], non-flaring Sun (blue) [5] and pre-flaring periods (purple) after having subtracted the main X-ray flare component [6], whose distribution coincides with that of the 'Active Sun' above 3 keV (not shown). Two thin lines, black and blue, show the expected shape of reconverted outstreaming solar axions at a depth of 400 km and 350 km below the solar surface, respectively.…”

“…Especially, the recently Patras 2009 directly measured quiet Sun spectrum above 1 keV with the SphinX mission [7] confirms a perfect linear shape. The figure also gives the directly measured spectral shape of the emitted X-rays from the non-flaring Sun [5], a solar flare [4] and pre-flaring periods [6]. It is interesting to point out here that nothing requires a solar emission to be always from a high-temperature plasma, though it is usually offered as the simplest explanation [8], even more so if its energy source is unknown (e.g.…”

From the geophysical to heliophysical year: The results of the CORONAS-F project

“…[17] The detailed spectroscopic diagnostics of the flare plasma and atomic processes in the flares were performed with the help of DIAGENESS spectrophotometer and RESIK X-ray spectrometer [Sylwester et al, 2005a[Sylwester et al, , 2005b. For the first time the absolute Doppler shifts of the X-ray spectral lines in solar flares and the absolute content of K (potassium) and CL (chlorine) in the solar corona were determined, and spectral lines of solar plasma ions for high values of the quantum numbers n (see Figure 7) opening new possibilities for a new method of the temperature diagnostics of the coronal plasma were detected.…”

Experimental dielectronic recombination rate coefficients for lithium-like 40Ca17+

“…Moreover, the emission lines from Be-like Ca XVII, B-like Ca XVI and C-like Ca XV ions have been also observed in x-ray and EUV ranges from several astrophysical sources and the details about these observations can be found in [52,53,56,[62][63][64] and references therein. In particular, the x-ray emission lines of Li-like Ca XVIII from astrophysical environment have been extensively observed in solar flare and solar active region with different observatories [65,66]. In EUV spectrum of the solar active region and solar flare the emission lines of Ca XVIII have been recorded with SERTS and CORONAS-F missions [67,68].…”