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_raw

[        carsus.io.vald.vald][   INFO] - Parsing VALD from: /tmp/vald_sample_linelist.dat (vald.py:163)
[        carsus.io.vald.vald][   INFO] - Found wavelength column header: WL_air(A) (vald.py:181)

	elm_ion	WL_air(A)	log_gf	e_low	j_lo	e_up	j_up	lande_lower	lande_upper	lande_mean	rad	stark	waals
0	'TiO 1'	4100.0002	-11.472	0.2011	31.0	3.2242	32.0	99.0	99.0	99.0	6.962	0.0	0.0
1	'TiO 1'	4100.0003	-4.037	0.7439	16.0	3.7670	15.0	99.0	99.0	99.0	7.264	0.0	0.0
2	'TiO 1'	4100.0005	-10.188	0.6244	88.0	3.6475	87.0	99.0	99.0	99.0	6.911	0.0	0.0
3	'TiO 1'	4100.0005	-9.915	0.0601	30.0	3.0832	31.0	99.0	99.0	99.0	4.830	0.0	0.0
4	'TiO 1'	4100.0008	-0.314	1.8211	139.0	4.8443	139.0	99.0	99.0	99.0	7.874	0.0	0.0
...	...	...	...	...	...	...	...	...	...	...	...	...	...
46858	'TiO 1'	4109.9989	-2.319	2.1318	161.0	5.1476	161.0	99.0	99.0	99.0	7.920	0.0	0.0
46859	'TiO 1'	4109.9991	-2.276	0.3773	44.0	3.3931	43.0	99.0	99.0	99.0	7.296	0.0	0.0
46860	'TiO 1'	4109.9995	-2.498	2.6005	135.0	5.6163	134.0	99.0	99.0	99.0	7.422	0.0	0.0
46861	'TiO 1'	4110.0000	-6.429	0.6188	75.0	3.6346	76.0	99.0	99.0	99.0	7.459	0.0	0.0
46862	'TiO 1'	4110.0000	-5.638	0.4544	56.0	3.4702	55.0	99.0	99.0	99.0	7.289	0.0	0.0

46863 rows × 13 columns

The reader parses the raw data and splits it into two linelist dataframes, either atomic or molecular.

Linelists only carry along the specific relevant information necessary to compute opacities. They can be accesed with the .linelist_atoms or .linelist_molecules attributes.

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

vald_reader.linelist_atoms

[                py.warnings][WARNING] - /home/shield90/miniconda3/envs/carsus/lib/python3.7/site-packages/pandas/core/indexing.py:845: SettingWithCopyWarning:
A value is trying to be set on a copy of a slice from a DataFrame.
Try using .loc[row_indexer,col_indexer] = value instead

See the caveats in the documentation: https://pandas.pydata.org/pandas-docs/stable/user_guide/indexing.html#returning-a-view-versus-a-copy
  self.obj[key] = _infer_fill_value(value)
 (warnings.py:110)
[                py.warnings][WARNING] - /home/shield90/miniconda3/envs/carsus/lib/python3.7/site-packages/pandas/core/indexing.py:966: SettingWithCopyWarning:
A value is trying to be set on a copy of a slice from a DataFrame.
Try using .loc[row_indexer,col_indexer] = value instead

See the caveats in the documentation: https://pandas.pydata.org/pandas-docs/stable/user_guide/indexing.html#returning-a-view-versus-a-copy
  self.obj[item] = s
 (warnings.py:110)
[                py.warnings][WARNING] - /home/shield90/miniconda3/envs/carsus/lib/python3.7/site-packages/pandas/core/frame.py:4133: SettingWithCopyWarning:
A value is trying to be set on a copy of a slice from a DataFrame

See the caveats in the documentation: https://pandas.pydata.org/pandas-docs/stable/user_guide/indexing.html#returning-a-view-versus-a-copy
  errors=errors,
 (warnings.py:110)

	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

vald_reader.linelist_molecules

	molecule	ion_charge	wavelength	log_gf	e_low	e_up	j_lo	j_up	rad	stark	waals
0	TiO	0	4101.157405	-11.472	0.2011	3.2242	31.0	32.0	6.962	0.0	0.0
1	TiO	0	4101.157505	-4.037	0.7439	3.7670	16.0	15.0	7.264	0.0	0.0
2	TiO	0	4101.157705	-10.188	0.6244	3.6475	88.0	87.0	6.911	0.0	0.0
3	TiO	0	4101.157705	-9.915	0.0601	3.0832	30.0	31.0	4.830	0.0	0.0
4	TiO	0	4101.158005	-0.314	1.8211	4.8443	139.0	139.0	7.874	0.0	0.0
...	...	...	...	...	...	...	...	...	...	...	...
46858	TiO	0	4111.158724	-2.319	2.1318	5.1476	161.0	161.0	7.920	0.0	0.0
46859	TiO	0	4111.158924	-2.276	0.3773	3.3931	44.0	43.0	7.296	0.0	0.0
46860	TiO	0	4111.159324	-2.498	2.6005	5.6163	135.0	134.0	7.422	0.0	0.0
46861	TiO	0	4111.159824	-6.429	0.6188	3.6346	75.0	76.0	7.459	0.0	0.0
46862	TiO	0	4111.159824	-5.638	0.4544	3.4702	56.0	55.0	7.289	0.0	0.0

45868 rows × 11 columns