UNIVERSITY OF CAMBRIDGE
Department of Applied Mathematics and Theoretical Physics

CHIANTI

A Database for Astrophysical Emission Line Spectroscopy

A key part of astronomy is the analysis of the spectrum of radiation emitted by a body, be it the Sun, other stars, galaxies or quasars. The ultraviolet portion of the spectra of most stars is dominated by emission lines resulting from electron transitions within high temperature ions present in the atmosphere of the stars.

For the interpretation of such spectra, it is necessary to have available large quantities of accurate atomic data that are up-to-date and in a consistent format. The CHIANTI database contains this data and is freely available to all researchers.

What is CHIANTI:

CHIANTI consists of a critically evaluated set of atomic data necessary to calculate the emission line spectrum of astrophysical plasmas. The data consists of atomic energy levels, atomic radiative data such as wavelengths, weighted oscillator strengths and A values, and electron collisional excitation rates. A set of programs that use these data to calculate the spectrum in a desired wavelength range as a function of temperature and density are also provided. These programs have been written in Interactive Data Language (IDL).

Here is an explanation with examples of the atomic data - directory structure and file contents.

Who has produced CHIANTI:

CHIANTI is a collaborative project involving the Naval Research Laboratory (Washington DC, USA), the Arcetri Observatory (Firenze, Italy), and the Cambridge University (United Kingdom).

The CHIANTI consortium members
Including a history of the database

The continued development of the CHIANTI database is dependent on continued funding which is generally available if we can demonstrate that the CHIANTI database is of use to astrophysical research. If you find CHIANTI useful, it would be helpful to us if you could email a short description (a single sentence is fine) of how you employ CHIANTI.

We are also aware that CHIANTI data is being ingested into other databases and this is fine. However, it would be useful for us if some acknowledgement of this use of CHIANTI can be given, such as in publications etc.

How to keep updated on future CHIANTI developments:

We maintain an e-mail list, that is used to distribute information about any developments of the CHIANTI database and programs. To get on the CHIANTI emailing list, send an email to Ken Dere

The database:

CHIANTI Version 3.0 Released !

CHIANTI has been extended to X-ray wavelengths below 50 Å

We would like to announce the release of Version 3.0 of the CHIANTI database for astrophysical spectroscopy. This now extends the database to include the 1 - 50 Å wavelength region. The additions to the database are described in a paper `CHIANTI - an atomic database for emission lines, IV - Extension to X-ray Wavelengths' by K.P. Dere, E. Landi, P.R. Young and G. Del Zanna, and has been submitted to the Astrophysical Journal Supplement Series.

* PLEASE NOTE * !

As for the previous versions of CHIANTI, users should be aware of what is included in the database, of the approximations applied, and of the atomic data used. The CHIANTI results should not be blindly considered valid in all cases. For example, the CHIANTI predicted emissivities should not be used when considering temperatures outside of the validity ranges.

If you already have a previous version of CHIANTI, it is necessary to download both the new data files and the new set of IDL procedures to run Version 3. In order to include dielectronic satellite lines, it has been necessary to modify our general procedures for calculating line intensities. Consequently, the new data set is not compatible with the old procedures and viceversa.

What's new in CHIANTI Version 3.0NEW!

Elements and ions in the database (NRL site) NEW!

Find out which elements and ions are now contained in CHIANTI ! This page has also links to pages where the references used for each ion are listed.

Downloading and running CHIANTI Version 3.0 - README

How to download the database, and a description of its contents programs and applications

Copies of the CHIANTI database are also maintained at the

The CHIANTI version 3 line list

Future developments of CHIANTI

CHIANTI will continue to grow in the future. We expect to work on the following areas in the near future:

Include proton excitation rates
Include new atomic data calculations.
Develop procedures that account for non-ionization equilibrium.
Develop procedures that account for opacity.

Any contributions to CHIANTI are welcomed.

CHIANTI publications

CHIANTI-related links

Latest news
Last updated 12-APR-99

	The CHIANTI Version 2.0 database How to download the database, and a description of its contents
	CDS CHIANTI routines Some additional IDL routines produced for use with the CHIANTI v.2 database, and in the CDS software
	Extra CHIANTI routines Some additional IDL routines produced by P.R Young for use with the CHIANTI v.2 database