J/ApJS/229/23 New FeI level energies from stellar spectra. II. (Peterson+, 2017)
New Fe I level energies and line identifications from stellar spectra.
II. Initial results from new ultraviolet spectra of metal-poor stars.
Peterson R.C., Kurucz R.L., Ayres T.R.
<Astrophys. J. Suppl. Ser., 229, 23-23 (2017)>
=2017ApJS..229...23P 2017ApJS..229...23P (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics ; Spectra, ultraviolet
Keywords: atomic data; line: identification; methods: laboratory: atomic;
techniques: spectroscopic; ultraviolet: stars
Abstract:
The Fe I spectrum is critical to many areas of astrophysics, yet many
of the high-lying levels remain uncharacterized. To remedy this
deficiency, Peterson & Kurucz (2015, J/ApJS/216/1) identified Fe I
lines in archival ultraviolet and optical spectra of metal-poor stars,
whose warm temperatures favor moderate Fe I excitation. Sixty-five new
levels were recovered, with 1500 detectable lines, including several
bound levels in the ionization continuum of Fe I. Here, we extend the
previous work by identifying 59 additional levels, with 1400
detectable lines, by incorporating new high-resolution UV spectra of
warm metal-poor stars recently obtained by the Hubble Space Telescope
Imaging Spectrograph. We provide gf values for these transitions, both
computed as well as adjusted to fit the stellar spectra. We also
expand our spectral calculations to the infrared, confirming three
levels by matching high-quality spectra of the Sun and two cool stars
in the H-band. The predicted gf values suggest that an additional 3700
Fe I lines should be detectable in existing solar infrared spectra.
Extending the empirical line identification work to the infrared would
help confirm additional Fe I levels, as would new high-resolution UV
spectra of metal-poor turnoff stars below 1900Å.
Description:
All of the new space-based UV spectra were obtained at a two-pixel
resolution of 110000 with the E230H echelle grating of the Space
Telescope Imaging Spectrograph (STIS) on HST, under program GO-14161
(R. Peterson, PI). See section 2 for further explanations.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 45 59 New Fe I levels and energies
table3.dat 96 10404 Newly classified lines of Fe I
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See also:
J/ApJS/216/1 : New FeI level energies from stellar spectra (Peterson+, 2015)
J/A+A/547/A108 : Comparative modelling of cool giants spectra
(Lebzelter+, 2012)
J/A+A/520/A57 : New FeII energy levels from stellar spectra (Castelli+, 2010)
J/A+AS/102/269 : Lab. and solar highly-excited levels of Fe I (Nave+ 1993)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1 A1 --- P e=even or o=odd levels
3- 22 A20 --- ExL Expanded label
24- 34 A11 --- Label Label
36 I1 --- J [0/7] Level J
38- 45 F8.2 cm-1 E [53591.5/67246.4] Energy
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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- 9 F9.4 nm lamAir [157.7/5997] Wavelength in air;
vacuum below 200nm
11- 16 F6.3 [-] log(gf) [-10/0.7] Log of calculated oscillator
strength times statistical weight of lower level
18 A1 --- l_dgf Upper limit on dgf if line not detected
19- 22 F4.1 --- dgf [-1.8/0.8]? If present, log(gf) which best
matches observed spectra is log(gf) - dgf
26- 34 F9.3 cm-1 E.e [0/67717] Even level energy
37- 39 F3.1 --- J.e [0/7] Even level J
41- 50 A10 --- Label.e Even level label
54- 62 F9.3 cm-1 E.o [19350.8/65590.6] Odd level energy
65- 67 F3.1 --- J.o [0/8] Odd level J
69- 78 A10 --- Label.o Odd level label
81- 84 F4.2 [-] Gam.R [6.7/9.1] Log radiative damping constant
86- 90 F5.2 [cm-3] Gam.S [-6.1/-2.3] Log Stark damping constant/electron
density
92- 96 F5.2 [cm-3] Gam.W [-7.8/-6.7] Log van der Waals damping
constant/hydrogen density
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History:
From electronic version of the journal
References:
Peterson & Kurucz. Paper I 2015ApJS..216....1P 2015ApJS..216....1P Cat. J/ApJS/216/1
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 14-Jun-2017