CHIANTI - an atomic database for emission lines

Abstract

Abstract. A comprehensive set of accurate atomic data is required for analyses of astrophysical and solar spectra. CHIANTI provides a database of atomic energy levels, wavelengths, radiative data and electron excitation data for ions which are abundant in cosmic plasmas. The most recent electron excitation data have been assessed and stored following the method of Burgess & Tully (1992). The current version is essentially complete for specifying the emission spectrum at wavelengths greater than 50Å. A list of observed lines in the spectral region between 50 and 1100Å has been compiled and compared with the lines predicted by the CHIANTI database. The CHIANTI database reproduces the vast majority of lines observed at these wavelengths. CHIANTI includes IDL (Interactive Data Language) routines to calculate optically thin synthetic spectra for equilibrium conditions. IDL routines to calculate theoretical line intensities required for electron density or temperature diagnostics and emission measure studies are also included. The CHIANTI atomic database and supporting IDL routines are available by anonymous FTP.

X-ray line coincidence photopumping in a solar flare

“…The CHIANTI synthetic flare spectrum (Dere et al 1997;Del Zanna et al 2015) indicates that, even in the absence of photopumping, the Ne ix 82.76Å transition should dominate the emission feature observed by Acton et al (1985), contributing at least 50 per cent to the total line flux, with Fe xx and Fe xxii providing the main blending transitions. Furthermore, the Acton et al flare spectrum also contains the Ne ix 1s 2 1 S 0 -1s2p 1 P 1 resonance line at 13.45Å and 1s 2 1 S 0 -1s2s 3 S 1 forbidden line at 13.70Å.…”

“…A synthetic solar flare spectrum calculated with the latest version (8.0.1) of the CHIANTI database (Dere et al 1997;Del Zanna et al 2015) with the coronal abundances of Schmelz et al (2012) indicates that Ne ix makes a contribution of less than 1 per cent to the total line flux in both instances, while solar flare observations confirm that the features are due to Fe xiv (Bhatia et al 1994) and O iv (Widing 1982). In the case of the 81.58Å transition, the predicted enhancement is too small to detect the feature, even under optimal conditions.…”

Line ratios for soft-x-ray emission following charge exchange betweenO8+and Kr

“…, and 3p 2 ( 3 P )-1s3p( 3 P ), respectively [36][37][38]. These peaks are from double-electron capture processes, and not included in our reported ratios here.…”

SDO/AIA and Hinode/EIS observations of interaction between an EUV wave and active region loops

“…Then we used eis auto fit.pro with a single Gaussian model to obtain spectral intensities, line widths and Doppler velocities. From the Si x λ258.37/λ261.04 line pair, we derived the coronal electron densities (Dere et al 1997). …”