VALD

VALD is a database of atomic and molecular transitions used to create accurate synthetic spectra of many astrophysical systems. More information, as well as linelists can be downloaded from the VALD website.

In this example, data was downloaded from the VALD website and extracted to /tmp/vald_sample_linelist.dat

NOTE:

from carsus.io.vald import VALDReader

vald_reader = VALDReader(fname='/tmp/vald_sample_linelist.dat')

Table information is parsed to a dataframe which can be accesed via the .vald attribute. The column information is described in https://articles.adsabs.harvard.edu/pdf/1995A%26AS..112..525P and is as follows:

Wavelength - either air or vacuum and in nanometers or angstroms: Wavelength of the line

log_gf: Log10 of the oscillator strength times the degeneracy of the lower level

e_low: Excitation energy of the lower level in ergs

j_lo: Principal quantum number of the lower level

e_up: Excitation energy of the upper level in ergs

j_up: Principal quantum number of the upper level

lande_lower: Lande factor of the lower level

lande_upper: Lande factor of the upper level

lande_mean: Mean lande factor

rad: log10 of the radiation damping constant in \((4\pi s)^{-1}\)

stark: log10 of the Stark damping constant at 10,000K in \((4\pi s N_e)^{-1}\)

waals: log10 of the Van Der Waals damping constant at 10,000K in \((4\pi s N_H)^{-1}\)

vald_reader.vald

[        carsus.io.vald.vald][   INFO] - Parsing VALD from: /tmp/vald_sample_linelist.dat (vald.py:149)
[        carsus.io.vald.vald][   INFO] - Found wavelength column header: WL_air(A) (vald.py:167)

	WL_air(A)	log_gf	e_low	j_lo	e_up	j_up	lande_lower	lande_upper	lande_mean	rad	stark	waals	chemical	ion_charge	wavelength	atomic_number
0	4100.00538	-1.169	8.1293	2.0	11.1524	3.0	1.04	1.00	0.96	8.70	-6.47	-7.860	Mn	1	4101.162586	25
1	4100.04321	-5.992	10.4673	1.5	13.4904	2.5	2.28	1.54	0.99	8.94	-5.86	-7.630	Fe	1	4101.200426	26
2	4100.04405	-0.440	16.8273	2.0	19.8504	1.0	1.40	1.48	1.36	9.48	-5.99	-7.710	Ti	2	4101.201266	22
3	4100.04800	-0.725	51.0168	3.5	54.0399	4.5	99.00	99.00	99.00	10.00	0.00	0.000	He	1	4101.205217	2
4	4100.04910	-7.287	15.2375	2.0	18.2606	1.0	1.47	3.00	0.71	9.47	-6.35	-7.850	Fe	2	4101.206318	26
...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...	...
990	4109.94851	-5.428	3.8470	2.0	6.8628	3.0	1.16	0.95	0.75	8.10	-6.16	-7.750	Cr	0	4111.108321	24
991	4109.94900	-1.227	10.6900	1.5	13.7058	2.5	99.00	99.00	99.00	0.00	0.00	-7.419	N	0	4111.108811	7
992	4109.95324	-2.671	4.6244	2.0	7.6402	1.0	1.00	0.83	1.08	7.47	-2.75	-6.710	Ca	0	4111.113052	20
993	4109.96777	-4.848	13.9360	5.0	16.9518	5.0	1.38	1.20	1.29	8.44	-5.18	-7.500	Cu	1	4111.127586	29
994	4109.98163	-3.441	4.5351	4.0	7.5509	3.0	1.07	1.25	0.79	7.61	-4.43	-7.320	Cr	0	4111.141449	24

995 rows × 16 columns

The specific relevant information is extracted and prepared as a linelist in the .linelist attribute.

Note that the wavelengths here are reformated to Angstroms and in vacuum wavelengths.

vald_reader.linelist

	atomic_number	ion_charge	wavelength	log_gf	e_low	e_up	j_lo	j_up	rad	stark	waals
0	25	1	4101.162586	-1.169	8.1293	11.1524	2.0	3.0	8.70	-6.47	-7.860
1	26	1	4101.200426	-5.992	10.4673	13.4904	1.5	2.5	8.94	-5.86	-7.630
2	22	2	4101.201266	-0.440	16.8273	19.8504	2.0	1.0	9.48	-5.99	-7.710
3	2	1	4101.205217	-0.725	51.0168	54.0399	3.5	4.5	10.00	0.00	0.000
4	26	2	4101.206318	-7.287	15.2375	18.2606	2.0	1.0	9.47	-6.35	-7.850
...	...	...	...	...	...	...	...	...	...	...	...
990	24	0	4111.108321	-5.428	3.8470	6.8628	2.0	3.0	8.10	-6.16	-7.750
991	7	0	4111.108811	-1.227	10.6900	13.7058	1.5	2.5	0.00	0.00	-7.419
992	20	0	4111.113052	-2.671	4.6244	7.6402	2.0	1.0	7.47	-2.75	-6.710
993	29	1	4111.127586	-4.848	13.9360	16.9518	5.0	5.0	8.44	-5.18	-7.500
994	24	0	4111.141449	-3.441	4.5351	7.5509	4.0	3.0	7.61	-4.43	-7.320

995 rows × 11 columns