J/ApJS/220/13 Co I transition probabilities (Lawler+, 2015)
Improved Co I log(gf) values and abundance determinations in the photospheres
of the Sun and metal-poor star HD 84937.
Lawler J.E., Sneden C., Cowan J.J.
<Astrophys. J. Suppl. Ser., 220, 13 (2015)>
=2015ApJS..220...13L 2015ApJS..220...13L (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics
Keywords: atomic data; stars: individual: HD 84937;
stars: Population II; Sun: abundances
Abstract:
New emission branching fraction measurements for 898 lines of the
first spectrum of cobalt (Co I) are determined from hollow cathode
lamp spectra recorded with the National Solar Observatory 1m Fourier
transform spectrometer on Kitt Peak, AZ and a high-resolution echelle
spectrometer. Published radiative lifetimes from laser induced
fluorescence measurements are combined with the branching fractions to
determine accurate absolute atomic transition probabilities for the
898 lines. Hyperfine structure (hfs) constants for levels of neutral
Co in the literature are surveyed and selected values are used to
generate complete hfs component patterns for 195 transitions of Co I.
These new laboratory data are applied to determine the Co abundance in
the Sun and metal-poor star HD 84937, yielding
logε(Co)=4.955±0.007 (σ=0.059) based on 82 Co I lines
and logε(Co)=2.785±0.008 (σ=0.065) based on 66 Co I
lines, respectively. A Saha or ionization balance test on the
photosphere of HD 84937 is performed using 16 UV lines of Co II, and
good agreement is found with the Co I result in this metal-poor
([FeI/H]=-2.32, [FeII/H]=-2.32) dwarf star. The resulting value of
[Co/Fe]=+0.14 supports a rise of Co/Fe at low metallicity that has
been suggested in other studies.
Description:
Data from two complementary spectrometers are used in this work on CoI
including both the 1m Fourier transform spectrometer (FTS) at the
National Solar Observatory (NSO) - 17 spectra between 1978 Sep 11 and
1997 Dec 20 - and a 3m focal length echelle spectrometer (2014 Aug 8
to 2015 Jan 16).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 69 898 Experimental atomic transition probabilities for
898 lines of Co I organized by increasing
wavelength in air
table7.dat 52 2915 *Hyperfine structure line component patterns for 195
transitions of 59Co I
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Note on table7.dat: computed from published hfs coefficients (see text),
energy levels of Pickering and Thorne et al. (1996ApJS..107..761P 1996ApJS..107..761P), and the
standard index of air (Peck and Reeder 1972JOSA...62..958P 1972JOSA...62..958P).
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See also:
J/ApJS/215/23 : FeI lifetime & branching fractions (Den Hartog+, 2014)
J/ApJS/215/20 : Vanadium log(gf) and transition probabilities (Lawler+, 2014)
J/ApJS/214/18 : VII log(gf) values, and V abundance in HD 84937 (Wood+ 2014)
J/MNRAS/441/3127 : FeI oscillator strengths for Gaia-ESO (Ruffoni+, 2014)
J/AJ/147/136 : Stars of very low metal abundance. VI. (Roederer+, 2014)
J/ApJS/211/20 : NiI transition probability measurements (Wood+, 2014)
J/ApJS/208/27 : Sun and HD 84937 TiII log(gf) and abundances (Wood+, 2013)
J/ApJS/194/35 : Atomic transition probabilities of Mn (Den Hartog+, 2011)
J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)
J/ApJ/667/1267 : CrI transition probabilities (Sobeck+, 2007)
J/A+A/404/187 : Equivalent widths for metal-poor stars (Gratton+, 2003)
J/AJ/120/1841 : Abundances & Kinematics of Halo & Disk Stars (Fulbright 2000)
J/A+AS/130/541 : Co II oscillator strengths (Raassen+ 1998)
J/A+AS/129/147 : Co II radiative transition probabilities (Quinet 1998)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 10 F10.4 0.1nm lamAir [2073.2/10382.4] Wavelength in air; in Å (1)
12- 20 F9.3 cm-1 Lev1 [28345.8/53822] Upper level (2)
22- 23 A2 --- P1 Upper level parity (2)
25- 27 F3.1 --- J1 [0.5/7.5] Upper level J value (2)
29- 37 F9.3 cm-1 Lev0 [0/28470.5] Lower level (2)
39- 40 A2 --- P0 Lower level parity (2)
42- 44 F3.1 --- J0 [0.5/6.5] Lower level J value (2)
46- 54 F9.5 10+6/s A [0.001/494] Transition probability
56- 63 F8.5 10+6/s e_A [0.0001/49] Total uncertainty in A
65- 69 F5.2 --- log(gf) [-4.7/0.8] Log of degeneracy times oscillator
strength
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Note (1): Computed from energy levels using the standard index of air
from Peck & Reeder (1972JOSA...62..958P 1972JOSA...62..958P).
Note (2): From Pickering & Thorne (1996ApJS..107..761P 1996ApJS..107..761P).
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 9 F9.3 cm-1 sig [9951/43555.2] Center-of-Gravity Wavenumber
11- 20 F10.4 0.1nm lamAir [2295.2/10046.5] Center-of-Gravity Air Wavelength
in Angstroms
22- 23 I2 --- F1 [0/10] Component upper level F or
total angular momentum
25 I1 --- F0 [0/9] Component lower level F or
total angular momentum
27- 34 F8.5 cm-1 dsig [-0.5/0.5] Component offset Wavenumber (1)
36- 44 F9.6 0.1nm dlam [-0.15/0.2] Component offset Wavelength; in Å (1)
46- 52 F7.5 --- Str [0/0.4] Component strength (2)
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Note (1): With respect to Center-of-gravity Wavenumber or Wavelength.
Note (2): Normalized to sum to one.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 06-Nov-2015