Atomic data for Stellar Atmospheres: lte

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Дата изменения: Thu Nov 15 23:49:29 2001
Дата индексирования: Sat Dec 22 01:47:05 2007
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Atomic data for Stellar Atmospheres: lte_lines

lte_lines: assessed atomic data for optical analyses of B stars

C.S. Jeffery, Armagh Observatory, College Hill, Armagh BT61 9DG, Northern Ireland
P.L. Dufton, School of Physics, Queens University Belfast, Belfast, Northern Ireland

For calculating model spectra of early-type helium stars in LTE, we maintain a database of atomic data for, mostly, blue-visual absorption lines of light elements. The data is sorted with one file for each ion.

For each absorption line included, the database includes the wavelength, oscillator strength, radiative, collisional and van der Waal's damping constants (where available), the excitation energy of the lower-level in the transition, the multplet number (from Moore's revised multiplet tables). A reference for each of the oscillator strengths and damping constants is also given. The database is dynamic, with new lines being added as required. Some vetting is applied to ensure that only the most reliable data are included. Consequently the database is quite dynamic, with corrections and updates being included at arbitrary times.

A combined linelist can be constructed for use (eg) with SPECTRUM by executing the C-Shell program lte_line. All the files necesary to run lte_line are available as a gzipped tar file. Usage should make reference to the original article describing this database (Jeffery C.S., 1991, Newsletter on 'Analysis of Astronomical Spectra', No. 16, p. 17), in addition to references to specific data sources.

2001 November

The linelists have been reformatted. Damping constants have been converted to natural gammas. Damping constants and oscillator strengths are now stored as logarithms. The conversion was carried out by Philip Dufton, QUB. Consequently the description by Jeffery (1991) is partially out of date as it refers to the units and format of the data.

A number of utilities used to convert various linelist formats have been developed over the years. These are provided here "as is" with no guarantees.

Information

File	HTML	Contents
		"read.me" file containing original ascii text for WWW pages
		Description of format and contents of ion files
		File to insert and mark the end of a linelist
		List of references to atomic data stored in ion files
		gzipped tar file

Linelists for individual ions

The number of lines in each file is given for each ion.

Ion	I = 0	II = +	III = ++	IV = +++
Helium	He I 367	He I 2
Lithium	Li I 2
Carbon	C I 15	C II 60	C III 27	C IV 10
Nitrogen		N II 220	N III 23
Oxygen	O I 6	O II 262	O III 6
Neon	Ne I 17	Ne II 33
Magnesium		Mg II 12
Aluminium		Al II 10	Al III 18
Silicon	Si I 1	Si II 19	Si III 26	Si IV 14
Phosphor		P II 24	P III 6	P IV 1
Sulphur		S II 88	S III 32
Chlorine		Cl II 33
Argon		A II 96
Calcium		Ca II 21
Titanium		Ti II 45
Chromium		Cr II 5
Iron	Fe I 101	Fe II 59	Fe III 12
Nickel

Major sources

Linelists compiled by the Queens University of Belfast Hot Star group
Linelists provided in the code of Uli Heber, atomic data is published for some of these lines by Heber 1983, AA 118,39, with references. Not all of the references have been entered. Much of the data is very old.
A compilation by Kilian et al (1990), preprint - Munich. This compilation selectively lists data for lines with B star equivalent widths predicted to be greater than 10 mA, so is not complete for all multiplets, and only for wavelengths 4050 - 5060 Angstroms.
Oscillator strengths from the Opacity Project.
Where data have been essential for synthesizing B star spectra, additional lines have been extracted from Kurucz' linelists.

Programs

lte_line	C-shell script to construct a composite linelist given specified ions
lte_conv	A Fortan utility to convert old linelist to new format. It will work on both complete linelists (including the atomic data at the start and references at the end) or raw ion files (such as Ni2.d).
	In fact spectrum is much more powerful than the B-star tag suggests. It may be used to model a wide variety of stellar spectra in LTE and HSE, providing they are warm enough not to contain molecules. Consequentky, more estensive linelists may be reuqired to construct genuinley useful synthetic spectra. There are many sources of atomic data; the following utilities enable these to be imcorporated with existing QUB linelists.
vald_qub	A Fortran utility to convert linelists downloaded from the Vienna Atomic Line Database into the new QUB format.
synspec_qub	A Fortran utility to convert linelists in SYNSPEC format into the new QUB format.
lte_select	A Fortran utility to manipulate QUB-format linelists. It starts by reading in an optional initial linelist (QUB format) which will not be changed. An additional linelist (QUB format) is read in, it may be in the form of a Hubeny list, sorted by wavelength, or in some other order. Individual lines may be selected using various criteria including one or more of the following: wavelength region ions oscillator strength Examples of use: 1. Starting with an assessed list (such as created by "lte_line"), add additional lines from large database (eg Kurucz & Petrymann) 2. Starting with a large database (eg Kurucz & Petrymann) build up a reduced list ion by ion

This page is maintained by:
Simon Jeffery (csj@star.arm.ac.uk)
Last modified: 13/11/01

Simon's home page

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