Solar Wind Charge Exchange X-Ray Emission in the Era of High Spectral ResolutionONLINE ONLY

Solar wind charge exchange X-ray (SWCX) emission was a surprising discovery in X-ray astrophysics in the late 1990’s. Initially discovered in comets, the emission is produced when highly charged ions in the solar wind collide with neutrals. The ion receives an electron in a highly excited state which emits X-ray photons as it cascades down to the ground state. Planetary and heliophysics scientists have recognized in this mechanism new opportunities to study the solar wind – exosphere / magnetosphere interactions. However, SWCX from the heliosphere has long been considered a hindrance to studies of more distant diffuse astrophysical sources. The diffuse and slowly varying signal, in contrast to the highly variable geocoronal SWCX emission, is the most difficult component to distinguish and separate from the diffuse X-ray background. The similarity of the SWCX spectrum to thermal emission at CCD resolution adds to the complexity of spectral data analysis. The advent of high-resolution microcalorimeter spectroscopy opens new paths to studying the solar system SWCX. In this talk, I will briefly recount how SWCX evolved from an astrophysical nuisance to a valuable tool for heliophysics. I will also present a few examples of SWCX studies that could be enabled by microcalorimeter instruments at 1-2 eV resolution. For the first time we will have access to key spectral diagnostics: resolving the triplet complexes of He-like ions (e.g. O VII, Ne IX) and historically inaccessible line species below 0.3 keV, as well as measuring thermal broadening and Doppler shifts. These novel diagnostic resources will need close collaboration between observers, modelers, theoreticians and experimenters to grasp the details of the CX mechanism, which is still relatively understudied.

https://gsi-fair.zoom.us/j/63856816325
Meeting-ID: 638 5681 6325
Passcode: AP_Seminar
dial by phone
+496938079884,,63856816325#,,,,*8527227260# Deutschland
+496950500951,,63856816325#,,,,*8527227260# Deutschland