We would like to announce the release of Version 2.0 of the CHIANTI database for astrophysical spectroscopy. The additions and corrections to the database have been described in a paper `CHIANTI - an atomic database for emission lines, III - Continuum radiation and extension of the ion database' by E. Landi, M. Landini, K.P. Dere, P.R. Young, H.E. Mason and has been published in Astronomy and Astrophysics Supplement Series, 135, 339 ,1999, (Paper III). The new material is described below but the primary goal of this release is to provide atomic data for many of the minor elements.

The best way to access CHIANTI is through our WWW page: http://wwwsolar.nrl.navy.mil/chianti.html

*** PLEASE NOTE *** The new tar files include a new version of the procedure 'read_ioneq.pro' which will be put in the !xuvtop/pro directory. If this is not your standard CHIANTI IDL procedures directory, it should be moved to that directory. We had not intended to change any of the procedures at this time but this was unavoidable.

Also, since we no longer distribute the .elvl files, which are made redundant by the .elvlc files, it is necessary to download Version 1.03 of the CHIANTI IDL procedures in the unix compressed tar file CHIANTI_1.03_pro.tar.Z. The updated programs no longer search for the .elvl files. This is an incremental update of the CHIANTI IDL procedures. One nice feature of Version 1.03 is that by typing the name of a procedure, while in IDL, it's correct calling sequence is returned.

New data includes the minor elements Na, P, Cl, K, Ti, Cr, Mn, Co and Zn as discussed by Landi and Landini, 1999, A&ASS, 133, 411.

Updates by iso-electronic sequence are as follows:
Beryllium sequence
Ne VII: new R-matrix calculations of Ramsbottom
Mg IX: new A values from SUPERSTRUCTURE calculations
S XIII, Ar XV, Ca XVII, Fe XXIII, Ni XXV: n=3 levels now included
Boron sequence
O IV: a collision strength affecting the lines at 608.397A and 609.829A has been corrected.
Ca XVI: a missing collision strength included
Carbon sequence
Al VIII, Ni XXIII: now included
Si IX: R-matrix calculations of Aggarwal used for ground transitiions
Nitrogen sequence
Ne IV: new R-matrix calculations of Ramsbottom
Mg VI: new Distorted Wave calculations of Bhatia and Young
Al VII, Ni XXII: now included
Fe XX: now includes 72 levels through n=3 from the DW calculations of Bhatia (1989)
Ni XXII: is not included (contrary to Paper III) because the interpolation was not considered reliable
Zn XXIV: data are included (contrary to Paper III)
Oxygen sequence
Al VI: now included
Fluorine sequence
Al V: now included
Aluminum sequence
Ni XVI: DW calculations of Bhatia and Doschek (1998)
Sulphur sequence
Fe XI: model refined
Ni XIII: DW calculations of Bhatia and Doschek (1998)
Chlorine sequence
Fe X: model refined
Ni XII: R-matrix calculations of Matthews et al (1998)
The references in the elemental abundance file feldman.abund has been corrected.
Ionization equilibria
The new ionization equilibria calculations of Mazzotta et al. 1998, A&ASS, 133, 403 have been included (mazzotta_etal.ioneq)
Other ionization equilibria calculations included:
- the calculations of Arnaud and Rothenflug, 1986, A&AS, 60, 425.
- the calculations of Arnaud and Rothenflug plus those of Landini and Monsignori Fossi, 1991, A&AS, 91, 183 for the minor elements
- the calculations of Arnaud and Rothenflug plus those of Arnaud and Raymond, 1992, ApJ, 398, 39 for the Fe ions.
- the same as arnaud_raymond.ioneq plus those of Landini and Monsignori Fossi for the minor elements
- calculations of Shull and van Steenberg, 1982, ApJSS, 48, 95
Differential Emission Measures
We have found the the DEM file for the quiet sun (quiet_sun.dem) is characteristic of a more active sun and have renamed this 'quiet_sun_old.dem' and have replaced this with a new file 'quiet_sun.dem' derived from the OSO-6 quiet sun spectra of Dupree.
It should be noted that many of the differential emission measures were derived with the coronal abundances of meyer. Consequently, using these DEMs with other abundance sets could be inappropriate and produce misleading intensities.

The continuum procedure will soon be adapted to the CHIANTI formats and will be released soon in an update to the CHIANTI IDL procedures. We are currently working to complete the database at X-ray wavelengths in time for the launch of AXAF.

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.

If you find any problems, please let us know.