VI/80 Opacities from the Opacity Project (Seaton+, 1995)
Opacities for stellar envelopes
Seaton M.J., Yan Y., Mihalas D., Pradhan A.K.
<Mon. Not. R. Astron. Soc. 266, 805 (1994)>
=1994MNRAS.266..805S 1994MNRAS.266..805S (SIMBAD/NED BibCode) (SYMP)
Fitting and smoothing of opacity data
Seaton M.J.
<Mon. Not. R. Astron. Soc. 265, L25 (1993)> (OPF)
=1994MNRAS.265L..25S 1994MNRAS.265L..25S (SIMBAD/NED BibCode)
Interpolation of Rosseland-mean opacities for variable X and Z
Seaton M.J.
<Mon. Not. R. Astron. Soc. 279, 95 (1996)> (IXZ)
=1996MNRAS.279...95S 1996MNRAS.279...95S
ADC_Keywords: Atomic physics ; Models, atmosphere
Keywords: Opacities
References:
Opacities from the Opacity Project. For general description see
M.J. Seaton, Yu Yan, D. Mihalas and Anil K. Pradhan,
1994MNRAS.266..805S 1994MNRAS.266..805S . This paper will be referred to as SYMP.
For interpolation of opacities as functions of temperature
and density see M.J. Seaton, 1993MNRAS.265L..25S 1993MNRAS.265L..25S .
This paper will be referred to as OPF.
For interpolations of opacities as functions of X (hydrogen mass-
fraction) and Z (metals mass-fraction), for fixed relative
abundances of metal atoms, see M.J. Seaton, 1996MNRAS.279...95S 1996MNRAS.279...95S .
This paper will be referred to as IXZ.
Description:
1 CODES.
*****
1.1 Code rop.for
************
This code reads opacity files written in standard OP format.
Its main purpose is to provide documentation on the contents of the
files.
This code, like the other codes provided, prompts for the name of
the file (or files) to be read.
The file names read in response to the prompt may have up to 128
characters.
1.2 Code opfit.for
**************
This code reads opacity files in standard OP format, and
provides for interpolation of opacities to any required values
of temperature and mass-density. The method used is described in OPF.
The code prompts for the name of a file giving all required control
parameters. As an example, the file opfit.dat is provided (users
will need to change directory names and file names).
The use of opfit.for is illustrated using opfit.dat.
Most users will probably want to adapt opfit.for for use as a subroutine
in other codes.
Timings for DEC 7000 ALPHA: 0.3 sec for data read and initialisations;
then 0.0007 sec for each temperature-density point.
Users who like OPAL formats should note that opfit.for has a facility
to produce files of OP data in OPAL-type formats.
1.3 Code ixz.for
************
This code provides for interpolations to any required values of X and
Z. See IXZ. It prompts for the name of a file giving all required control
parameters. An example of such a file if provided, ixz.dat (the user
will need to change directory and file names).
The output files have names s92INT.'nnn'. The user specifies the first
value of nnn, and the number of files to be produced.
2. DATA FILES
**********
2.1 Data files for solar metal-mix
******************************
Data for solar metal-mix s92 as defined in SYMP. These files are
from version 2 runs of December 1994 (see IXZ for details on Version 2).
There are 213 files with names s92.'nnn', 'nnn'=201 to 413.
Each file occupies 83762 bytes.
The file s92.version2 gives values of X (hydrogen mass-faction) and
Z (metals mass-fraction) for each value of 'nnn'. The user can get
s92.version2, select the values of 'nnn' required, then get the
required files s92.'nnn'. The user can see the file in ftp,
displayed on the screen, by typing "get s92.version2 -".
The files s92.'nnn' can be used with opfit.for to obtain opacities
for any requires value of temperature and mass density.
Files for other metal-mixtures will be added in due course.
Send requests to
2.2 Files for interpolation in X and Z
**********************************
The data files have names s92xz.'mmm', where 'mmm'=001 to 096.
They differ from the standard OP files (such as s92.'nnn' ---
section 2.1 above) in that they contain information
giving derivatives of opacities with respect to X and Z.
Each file s92xz.'mmm' occupies 148241 bytes.
The interpolations to any required values of X and Z are made using
ixz.for.
Timings: on DEC 7000 ALPHA, 2.16 sec for each new-mixture file.
For interpolations to some specified values of X and Z, one requires just
4 files s92xz.'mmm'. Most users will not require the complete set
of files s92xz.'mmm'. The file s92xz.index includes a table (starting
on line 3) giving values, for each 'mmm' file, of x,y,z (abundances by
number-factions) and X,Y,Z (abundances by mass-fractions). Users are
advised to get the file s92.index, and select values of 'mmm' for
files required, then get those files.
The files produced by ixz.for are in standard OP format and can be
used with opfit.for to obtain opacities for any required values of
temperature and mass density.
3 RECOMMENDED PROCEDURE FOR USE OF OPACITY FILES
**********************************************
(1) Get the file s92.version2.
(2) If the values of X and Z you require are available in the
files s92.'nnn' then get those files.
(3) If not, get the file s92xz.index.
(4) Select from s92xz.index the values of 'mmm' which cover the
range of X and Z in which your are interested. Get those
files and use ixz.for to generate files for your exact
required values of X and Z.
(5) Note that the exact abundance mixtures used are specified in each
file (see rop.for). Also each run of opfit.for produces a
table of abundances.
(6) If you want a metal-mix different from that of s92, contact
4 FUTURE DEVELOPMENTS
*******************
(1) Data for the calculation of radiative forces are provided as the
CDS catalog VI/89 (added August 1997)
(2) Facilities will be added later which will enable the user
to make calculations giving files for any required mixtures.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
rop.for 76 82 Code to read opacity files (s92.* files)
opfit.for 74 982 Code to read opacity files and interpolate
to any temperature and mass-density.
ixz.for 72 725 Code for interpolations to any X and Z values
ixz.dat 20 9 Example of input for ixz code
opfit.dat 27 6 Example of input for opfit code
s92.version2 63 213 Summary of solar metal-mix s92 data
s92.* 63 406830 Solar metal-mix s92 as defined in SYMP in
standard OP format (213 files)
s92xz.* 80 181632 Opacity derivatives with respect to X and Z
(96 files)
s92xz.index 80 2010 Summary of s92xz.* files
--------------------------------------------------------------------------------
See also:
VI/89 : Radiative forces for stellar envelopes (Seaton, 1997)
http://cdsweb.u-strasbg.fr/cgi-bin/OP : Interactive opacity computations.
Byte-by-byte Description of file: s92.version2
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
2- 19 A18 --- Version Version designation "OP Version 2.0 S92"
21- 23 I3 --- Mix [201/413]+ Mixture number
27- 28 A2 --- --- "X="
30- 38 E9.3 --- X [0/1] Hydrogen mass-fraction
39- 42 A4 --- --- ", Z="
44- 52 E9.3 --- Z [0/1] Metal (Z≥3) mass-fraction
56- 62 A7 --- Date Computation date
--------------------------------------------------------------------------------
(End) Mike J. Seaton [Univ. Coll. London] 18-Apr-1995, rev. 08-Aug-1997