J/A+A/465/271 Oxygen abundances in nearby stars (Ramirez+, 2007)
Oxygen abundances in nearby stars. Clues to the formation and evolution of the
Galactic disk.
Ramirez, I., Allende Prieto, C., Lambert, D.L.
<Astron. Astrophys. 465, 271 (2007)>
=2007A&A...465..271R 2007A&A...465..271R
ADC_Keywords: Stars, nearby ; Radial velocities ; Space velocities ; Abundances
Keywords: stars: abundances - stars: atmospheres -
stars: fundamental parameters - Galaxy: disk
Abstract:
The abundances of iron and oxygen are homogeneously determined in a
sample of 523 nearby (d<150pc) FGK disk and halo stars with
metallicities in the range -1.5<[Fe/H]<0.5. Iron abundances were
obtained from an LTE analysis of a large set of FeI and FeII lines
with reliable atomic data. Oxygen abundances were inferred from a
restricted non-LTE analysis of the 777nm OI triplet. We adopted the
infrared flux method temperature scale and surface gravities based on
Hipparcos trigonometric parallaxes.
Description:
We provide in Table 4 basic (HIP and HD numbers, V magnitude and
parallax) and kinematic (radial velocities and heliocentric space
velocity) data for our sample stars. The kinematic probabilities of
being a thin-disk, thick-disk, and halo member are also given.
Table 5 contains the line data used in our abundance computations as
well as the equivalent widths of the lines measured in the solar
spectrum. Stellar parameters and abundances are given in Table 6.
Effective temperatures were derived using color calibrations based on
the infrared flux method temperature scale while surface gravities
were determined from the Hipparcos parallaxes and estimates of the
stellar masses based on theoretical isochrones. We provide the mean
abundance of iron determined from Fe I and Fe II lines separately and
a mean [Fe/H] value obtained after applying our empirical re-scaling
of the Fe I abundances. LTE and non-LTE oxygen abundances derived from
the 777nm OI triplet are also given. The last three columns of
Table 6, if available, provide our estimates of the stellar ages.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 96 523 Basic and kinematic data
table5.dat 41 135 Line data
table6.dat 104 523 Fundamental parameters, abundances and ages
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See also:
I/239 : The Hipparcos and Tycho Catalogues (ESA 1997)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HIP Hipparcos number (Cat. I/239)
8- 13 I6 --- HD ? HD number (Cat. III/135) if available
15- 19 F5.2 mag Vmag V magnitude
21- 25 F5.1 mas plx Parallax
27- 29 F3.1 mas e_plx Error in parallax
31- 36 F6.1 km/s HRV Heliocentric radial velocity
38- 42 F5.1 km/s e_HRV Error in HRV
44- 49 F6.1 km/s UVel Heliocentric space velocity component U
51- 55 F5.1 km/s e_UVel Error in UVel
57- 62 F6.1 km/s VVel Heliocentric space velocity component V
64- 68 F5.1 km/s e_VVel Error in VVel
70- 75 F6.1 km/s WVel Heliocentric space velocity component W
77- 81 F5.1 km/s e_WVel Error in WVel
83- 86 F4.2 --- P1 Kinematic probability of being thin-disk star
88- 91 F4.2 --- P2 Kinematic probability of being thick-disk star
93- 96 F4.2 --- P3 Kinematic probability of being halo star
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 7 F7.2 0.1nm Lambda Line wavelength
9- 12 A4 --- Ion Element and ionization stage
14- 17 F4.2 eV EP Excitation potential
19- 23 F5.2 [---] loggf Oscillator strength
25- 28 I4 2.8x10-17cm+2 sigma Van der Waals broadening cross section (1)
30- 34 F5.3 --- alpha Velocity parameter alpha (2)
36 A1 --- f_sigma [+] Unsold approximation for sigma (3)
38- 41 F4.1 0.1pm EWsun Equivalent width in the solar spectrum
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Note (1): Van der Waals broadening cross section in atomic unit:
1 a.u. = 2.80*10-17cm2
Note (2): alpha is defined as σ(V)=σ(Vo)(V/Vo)-α,
where V is the velocity and sigma the cross-section.
Note (3): the '+' indicates that sigma and alpha values correspond to
the modified Unsold approximation (Unsold C6 multiplied by 2)
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 6 I6 --- HIP Hipparcos number (Cat. I/239)
8- 13 I6 --- HD ? HD number (Cat. III/135) if available
15- 18 I4 K Teff Effective temperature
20- 23 F4.2 [cm/s2] logg Surface gravity
25- 28 F4.2 km/s vt Microturbulence velocity
30- 34 F5.2 [Sun] [Fe/H]1 Mean [Fe/H] from Fe I lines
36- 39 F4.2 [Sun] e_[Fe/H]1 Error in mean [Fe/H] from Fe I lines
41- 45 F5.2 [Sun] [Fe/H]2 Mean of [Fe/H] from Fe II lines
47- 50 F4.2 [Sun] e_[Fe/H]2 Error in mean [Fe/H] from Fe II lines
52- 56 F5.2 [Sun] [Fe/H] ? Adopted [Fe/H]
58- 61 F4.2 [Sun] e_[Fe/H] ? Error in adopted [Fe/H]
63- 67 F5.2 [Sun] [O/H]L LTE oxygen abundance
69- 72 F4.2 [Sun] e_[O/H]L Error in [O/H]L
74- 78 F5.2 [Sun] [O/H]N Non-LTE oxygen abundance
80- 83 F4.2 [Sun] e_[O/H]N Error in [O/H]N
85- 90 F6.3 [yr] logAge ? Stellar age
92- 97 F6.3 [yr] E_logAge ? Upper error bar in logAge
99-104 F6.3 [yr] e_logAge ? Lower error bar in logAge
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Acknowledgements:
Ivan Ramirez, ivan(at)astro.as.utexas.edu
(End) Patricia Vannier [CDS] 08-Jan-2007