CHIANTI version 9 release

April 2, 2019, from Giulio Del Zanna

With Version 9.0, CHIANTI explicitly includes the processes of dielectronic recombination and autoionization. While this does not significantly change the predicted spectrum at low densities, it allows for the exploration of the density sensitivity of some of the satellite lines at high densities. The atomic models for which these changes have been implemented include lithium sequence ions with significant astrophysical abundances and the iron ions Fe XVIII through Fe XXIII.

In addition, existing datasets have been updated and new ions added. New total recombination rates for several Fe ions are included and the ionization equilibrium has been recomputed.

A new file type, with a filename suffix .auto, contains the autoionization rates for a given ion, such as for Fe XVIII.
The rates of the autoionizing states have been added to the CHIANTI files. New level-resolved radiative recombination files have also been added.
Consequently, the new database and IDL programs are incompatible with the previous CHIANTI versions and vice-versa.
Details are given in the user guide, see our web site

If you use CHIANTI through SolarSoft that is automatically mirrored, the update will occur automatically. Otherwise, you will need to manually update the SolarSoft directories.

A new Version 8.0.2 release of ChiantiPy, maintained by K.Dere and compatible with the CHIANTI v.9 files, can be found on Github