CHIANTI Version 3.0

July 13, 2000

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CHIANTI consists of a database of atomic data and IDL procedures for
calculating spectroscopic emission line intensities from optically thin
astrophysical spectra as a function of density and temperature. The original
paper describing the database has appeared in 1997 in Astronomy and
Astrophysics Supplement Series, 125, 149, authored by K. P. Dere (NRL), E.
Landi (U. Florence), H. E. Mason (U. Cambridge), B. Monsignori Fossi
(Arcetri) and P. R. Young (U. Cambridge). With Version 3.0, the database has
now been extended into the 1-50Å wavelength region.

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The database consists of 3 primary ASCII files for each ion in the database.
Once the database is installed on your computer, the files will be placed in
a directory tree with the base being designated 'xuvtop'. The file name
prefix for each ion follows spectroscopic notation: for 3 times ionized
carbon in the lithium isoelectronic sequence C IV, the file name suffix is
'c_4.' All of the primary files for c_4 are then located in the directory
xuvtop/c/c_4. The primary files for c_4 are:

     c_4.elvlc specifies the energy levels in cm-1 and Rydbergs. It includes
     both experimental data and theoretical values of the levels energies.

     c_4.wgfa specifies the wavelengths, gf and A values of the transitions
     and the indices initial and final level corresponding to the indices of
     the levels as given in the c_4.elvlc file. Wavelengths calculated from
     the theoretical energies are of an indeterminate accuracy and their
     values are presented as negative values of the calculated wavelength.
     The wavelengths in these files that are based on experimental should be
     the best available.

     c_4.splups contains 5 point spline fits to electron collision strengths
     scaled according the rules formulated by Burgess and Tully (1992).
     Accurate replication of the temperature averaged collision strength
     over a wide range of temperatures can be accomplished with the data in
     this file.

The basic structure of the files is to put the data at the beginning of the
file followed by a single line containing a '-1' in the first 2 columns
followed by lines containing information such as the file name, references
to the original data in the scientific literature coupled to a keyword,
comments on the development of the file, followed by a single line with a
'-1' in the first 2 columns to signify the end of the file.

A 'masterlist.ions' file keeps a list of all the ions in the database and it
is in the xuvtop/masterlist directory. This is used by a number of programs
to determine which ions can be included in the calculation. It is an ascii
file and can be edited by the user to suit their purpose. However, it would
always be useful to keep a backup copy of the original. A number of other
files are supplied with the database. Files give various compilations of
elemental abundances are in the directory xuvtop/abund. Files giving
collisional ionization equilibria are in the xuvtop/ioneq directory.
Currently, files containing the ionization equilibrium of Arnaud and
Rothenflug (1985), Arnaud and Raymond (1992) and versions of these files
containing the ionization equilibria of the minor ions calculated by Landini
and Monsignori Fossi (1991), are included. Files specifying the differential
emission for various solar features. You are free to add your own files to
these directories.

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A number of Interactive Data Language (IDL) procedures are provided. These
include utiltiy routines to read the various CHIANTI database files, and
routines to calculate levels populations, line intensities, and temperature
dependent and density dependent line intensity ratios. Most of our efforts
have gone into developing the database and the IDL routines that exist have
been written to meet readily apparent needs. We will continue work on IDL
procedures but we expect that end-users will probably want to develop their
own IDL (or Fortran or C) programs to meet their own specific interests. A
short description of the various programs is available on the CHIANTI WWW
homepage. To date, CHIANTI has been run mainly on Sun and Dec Unix
workstations. Recent changes allow CHIANTI to run on VMS machines but this
capability has not been completely tested.

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

     1. Include proton excitation rates
     2. Develop procedures that account for opacity.
     3. Include new atomic data calculations.

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HOW TO DOWNLOAD CHIANTI

The CHIANTI database and IDL procedures are available for downloading from
louis14.nrl.navy.mil (132.250.160.129), either via an anonymous ftp account
or with a World-Wide-Web browser.

By anonymous ftp:

> ftp louis14.nrl.navy.mil
> Name: anonymous (type in anonymous)
> Password: type in your email address, such as: dere@halcyon.nrl.navy.m
> cd pub/chianti
> binary
> get CHIANTI_3.0_data.tar.Z
> get CHIANTI_3.0_pro.tar.Z
> quit
For most users, the 'lite' data file will be sufficient. It is smaller and
contains only the files necessary to calculate spectra.
> get CHIANTI_3.0_data_lite.tar.Z

If you already have CHIANTI installed, previous version are incompatible
with Version 3.0 and both the Version 3.0 data and IDL procedure files
should be downloaded.

and unpack it in the same manner.

By a WWW browser:

go to the CHIANTI homepage:

http://wwwsolar.nrl.navy.mil/chianti.html

HOW TO UNPACK CHIANTI

Move the compressed tar file CHIANTI_3.0_data.tar.Z to a (preferably new)
directory. The size of the tar file is about 9 Mbytes. For example, create
the directory /data1/chianti and move the tar file there. Then:

> uncompress CHIANTI_3.0_data.tar.Z
> tar xvf CHIANTI_3.0_data.tar

This will copy all the CHIANTI files into a new directory tree. For example,
the file c_4.elvlc will be /data1/chianti/c/c_4/c_4.elvlc. Note, if you use
gnu tar, then it is necessary to type 'tar -xvf ...'.

to unpack the IDL routines. Create the directory /data1/chianti/pro and move
the compressed tar file CHIANTI_3.0_pro.tar.Z to that directory

> uncompress CHIANTI_3.0_pro.tar.Z
> tar xvf CHIANTI_3.0_pro.tar

all the file should now be in the necessary locations.

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TO RUN CHIANTI IDL PROCEDURES

First, it is necessary to tell IDL where the CHIANTI IDL procedures are. Put
the following 2 statements into your .cshrc file or its equivalent.

> setenv IDL_PATH {$IDL_PATH}:/data1/chianti/pro
> setenv IDL_STARTUP ~/idl_startup

The second statement tells IDL that you have an IDL startup file named
idl_startup in your home directory. If you already have one, use that. Then,
include the next two statements in your idl_startup file:

defsysv,'!xuvtop','/data1/chianti'
defsysv,'!ioneq_file','mazzotta_etal.ioneq'

The second statement defines the default ionization equilibrium file and you
can change this to others in the 'xuvtop/ioneq' directory. If you did not
previously have an idl_startup file, you should create one which would
consist of a text file containing these two statements and any others that
you might want to add. Remember that you should substitute the proper
directory name for '/data1/chianti' in all these steps.

EXAMPLES of CHIANTI IDL ROUTINES

To run IDL, first make sure that these environment variables have been set.
Either open a new window or source ~/.cshrc. You can check the environment
variables with commands such as printenv or env. You should be ready to run
IDL:

> idl

As an example of CHIANTI procedures to try, plot the density sensitive line
ratios of O V lines in the 1000 to 1500 Å wavelength region for densities
between 108 and 1013 cm-3:

idl> density_ratios,'o_5',1000.,1500.,8.,13.,den,rat,desc

2 windows will open and plot the relative intensities of 3 lines of O V. A
widget will then appear to allow you to chose the line for the numerator of
the ratio. Select 2 (1371) and then click on 'Continue'. Another widget will
appear to select the denominator. Select 1 (1218) and then click on
'Continue'. This will chose the ratio of 1371.294 to 1218.393 which will be
plotted in a new window. Values of the density and intensity ratio will be
put into the variables den and rat and desc will contain a descriptive
string.

idl> print, desc
idl> O V 1371.294/1218.393

To calculate temperature sensitive line ratios of C IV for lines between 100
and 1600 Å for temperatures between 104 and 106 K:

>temperature_ratios,'c_4',100.,1600.,4.,6.,temp,rat,desc

As with density_ratios, a widget will appear that will allow you to select
the numerator. Select 3 (384.173) and 3 (384.189) as these will typically be
blended in most spectrographs. Then click on 'Continue'. Select 8 (1550.772)
for the denominator and then click on 'Continue'. The ratio of (384.173 +
384.189) to 1550.772 as a function of temperature will be plotted and stored
in the variables rat and temp, respectively.

idl>print, desc
idl> C IV 384.173 + 384.189/1550.772

To plot the level populations of the first 4 levels of Si III as a function
of density at a temperature of 3 x 104 K:

>plot_populations,'si_3',3.e+4,4

To create a latex file of a list of line intensities (erg cm-2 s-1 str-1)
between 100 and 200 Å for a specified set of abundances and differential
emission measure at a constant pressure of 1.e+15 (Ne T cm-3K):

>latex_wvl_dem,100.,200.,1.e+15,mini=1.

windows will pop up so that you can select the abundance file, the
ionization equilibrium (one choice) and the differential emission measure.
This will create a file linelist.tex in the user's home directory. Only
lines with an intensity greater than 1. (mini) are included in the file.

To create a synthetic spectrum with a resolution of 1 Å between 100 and 200
Å for a specified set of abundances and differential emission measure at a
constant pressure of 1.e+15 (Ne T cm-3 K):

>synthetic, 100., 200., 1., 1.e+15, wvl, spectrum, list_wvl, list_ident

windows will pop up so that you can select the abundance file, the
ionization equilibrium (one choice) and the differential emission measure. A
spectrum convolved with a Gaussian with a fwhm of 1 Å will then be stored in
the variables wvl and spectrum which can be plotted out.

If the /cont keyword had been set, then the continuum would also have been
calculated. This can be a fairly time-consuming calculation.

To plot the spectrum and interactively identify lines:

>synthetic_plot, wvl, spectrum, list_wvl, list_ident, 2.

by clicking the left mouse button, a list of predicted lines within 2 Å of
the selected wavelength will be printed out along with their predicted
intensity. Clicking the right mouse button will exit the procedure.

To calculate the free-free continuum intensity per unit emission measure
(10-40 erg cm-2 s-1 str-1 Å-1 cm5) at a temperature of 1.e+6 K,for
wavelengths at 1 Å intervals between 1 and 50Å:

>freefree,1.e+6,findgen(50)+1.,ff

To calculate the contribution function (erg cm-2 s-1 str-1 cm5) vs.
temperature at a specified abundance, ionization equilibrium and pressure or
density for the Fe XXIV line at 255.1Å:

>gofnt,'fe_24',250.,260.,temperature,g,desc

Descriptions of the various IDL routines can be found on the CHIANTI Web
page. One thing that you may have noticed is that CHIANTI can be slow. This
is largely because some of the ions, such as in the boron isoelectronic
sequence, contain over 100 energy levels. Solving the levels populations in
these cases can be time consuming.

If you have any questions or comments, the responsible parties are:

Ken Dere dere@halcyon.nrl.navy.mil
Enrico Landi enricol@arcetri.astro.it
Massimo Landini landini@arcetri.astro.it
Helen Mason H.E.Mason@damtp.cam.ac.uk
Peter Young pry10@damtp.cam.ac.uk
Giulio Del Zanna G.Del-Zanna@damtp.cam.ac.uk>BR>
If you would like to get on a mailing list to get news about future progress
with CHIANTI, send mail to Ken Dere

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