J/ApJS/216/1 New FeI level energies from stellar spectra (Peterson+, 2015)
New Fe I level energies and line identifications from stellar spectra.
Peterson R.C., Kurucz R.L.
<Astrophys. J. Suppl. Ser., 216, 1 (2015)>
=2015ApJS..216....1P 2015ApJS..216....1P
ADC_Keywords: Atomic physics ; Line Profiles ; Spectroscopy
Keywords: atomic data; line: identification; methods: laboratory: atomic;
stars: individual: (HD 29139, HD 72660, HD 76932, HD 85503, HD 94028,
HD 124897, HD 140283, HD 157466, HD 160617, HD 165341, HD 184499,
HD 211998, HD 217107); techniques: spectroscopic; ultraviolet: stars
Abstract:
The spectrum of the Fe I atom is critical to many areas of
astrophysics and beyond. Measurements of the energies of its
high-lying levels remain woefully incomplete, however, despite
extensive laboratory and solar analysis. In this work, we use
high-resolution archival absorption-line ultraviolet and optical
spectra of stars whose warm temperatures favor moderate Fe I
excitation. We derive the energy for a particular upper level in
Kurucz's semiempirical calculations by adopting a trial value that
yields the same wavelength for a given line predicted to be about as
strong as that of a strong unidentified spectral line observed in the
stellar spectra, then checking the new wavelengths of other strong
predicted transitions that share the same upper level for coincidence
with other strong observed unidentified lines. To date, this analysis
has provided the upper energies of 66 Fe I levels. Many new energy
levels are higher than those accessible to laboratory experiments;
several exceed the Fe I ionization energy. These levels provide new
identifications for over 2000 potentially detectable lines. Almost all
of the new levels of odd parity include UV lines that were detected
but unclassified in laboratory Fe I absorption spectra, providing an
external check on the energy values. We motivate and present the
procedure, provide the resulting new energy levels and their
uncertainties, list all the potentially detectable UV and optical new
Fe I line identifications and their gf values, point out new lines of
astrophysical interest, and discuss the prospects for additional Fe I
energy level determinations.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 113 33 Stellar parameters and spectra
table2.dat 48 65 New FeI levels and energies
table3.dat 98 1568 Newly classified lines of FeI
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See also:
J/ApJS/215/23 : FeI radiative lifetimes (Den Hartog+, 2014)
J/MNRAS/441/3127 : FeI oscillator strengths for Gaia-ESO (Ruffoni+, 2014)
J/A+A/554/A132 : Iron line list (FeI and FeII) (Genovali+, 2013)
J/A+A/547/A108 : Comparative modelling of giants spectra (Lebzelter+, 2012)
J/A+A/538/A143 : Atmospheric param. of stars for UV models (Koleva+, 2012)
J/ApJ/743/140 : Abundances in metal-poor stars (Boesgaard+, 2011)
J/A+A/520/A57 : New FeII energy levels from star spectra (Castelli+, 2010)
J/ApJS/187/149 : StarCAT: STIS UV echelle spectra of stars (Ayres, 2010)
J/ApJS/94/221 : New multiplet table for FeI (Nave+, 1994)
J/A+AS/102/269 : Lab. and solar highly-excited levels of Fe I (Nave+ 1993)
J/A+A/274/555 : FeI lines asymmetry in solar spectrum (Stathopoulou+ 1993)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 15 A15 --- ID Star name or model ID (Teff logg [Fe/H])
17- 35 A19 --- AName Alternative star name(s)
37- 40 I4 0.1nm lambda1 Lower range of wavelength in Å
41 A1 --- --- [-]
42- 46 I5 0.1nm lambda2 Upper range of wavelength in Å
48- 62 A15 --- Inst Telescope and Instrument
64- 84 A21 --- Prog Program
86-107 A22 --- Red Reduction method (1)
109-113 F5.2 ks Texp [0.01/63]? Exposure time
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Note (1): Keys to references are:
K05 = Kurucz, R. L. 2005, Kitt Peak Solar Flux Atlas available at
http://kurucz.harvard.edu/sun/fluxatlas2005
L12 = Lebzelter et al. 2012, Cat. J/A+A/547/A108
H00 = Hinkle et al. 2000vnia.book.....H 2000vnia.book.....H
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1 A1 --- P Parity level (e=even or o=odd)
3- 21 A19 --- ExpLevel Expanded label (1)
23- 32 A10 --- Level Abbreviated label (1)
34 I1 --- J [0/6] J value
36- 43 F8.2 cm-1 E [38602/67717] Energy
45- 48 F4.2 cm-1 e_E [0.01/0.1] 1σ uncertainty in wavenumber
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Note (1): The identification is a label, not a definitive assignment,
especially for levels that are highly mixed. See section 7.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 11 F11.4 nm lamAir [160.5/898.2] Wavelength in air;
vacuum below 200nm
13- 18 F6.3 [-] log(gf) [-4/0.4] Log of calculated oscillator strength
times statistical weight of lower level (1)
20- 24 F5.2 --- dgf [-1.4/0.9]? difference of log(gf) which best
matches the observed spectra - log(gf)
28- 36 F9.3 cm-1 E.e [0/67717] Even level energy
39- 41 F3.1 --- J.e [0/6] Even level J
43- 52 A10 --- Label.e Even level label
56- 64 F9.3 cm-1 E.o [19350/62885] Odd level energy
67- 69 F3.1 --- J.o [0/7] Odd level J
71- 80 A10 --- Label.o Odd level label
83- 86 F4.2 [-] Gam.R [6.8/8.9] Log radiative damping constant
88- 92 F5.2 [-] Gam.S Log Stark damping constant/electron density cm-3
94- 98 F5.2 [-] Gam.W Log van der Waals damping constant/H density cm-3
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Note (1): For each line sufficiently strong and unblended, we estimate a gf
value good to ±0.2dex above 2617Å. Blueward, gf value
uncertainties rise to ±0.4dex, as blends are poorly understood due
to the lack of high-resolution spectra for stars with -2≤[Fe/H]≤-1
(Table 1). Even larger uncertainties apply in the 2150-2380Å
region, where HD 140283 is the only star with high-resolution spectra
(Table 1), and below 1950Å, where line blending sharply increases
and signal to noise drops (Peterson 2011ApJ...742...21P 2011ApJ...742...21P).
See section 7.
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History:
From electronic version of the journal
References:
Peterson et al. Paper II. 2017ApJS..229...23P 2017ApJS..229...23P Cat. J/ApJS/229/23
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 10-Feb-2015