J/A+A/539/A143 Nearby B-stars stellar parameters and abundances (Nieva+, 2012)
Present-day cosmic abundances. A comprehensive study of nearby early
B-type stars and implications for stellar and Galactic evolution, and
interstellar dust models.
Nieva M.F., Przybilla N.
<Astron. Astrophys. 539, A143 (2012)>
=2012A&A...539A.143N 2012A&A...539A.143N
ADC_Keywords: Stars, B-type ; Stars, nearby ; Abundances ;
Effective temperatures ; Stars, distances
Keywords: stars: abundances - stars: early-type -
stars: fundamental parameters - stars: evolution - ISM: abundances -
Galaxy: evolution
Abstract:
Early B-type stars are ideal indicators for present-day cosmic
abundances since they preserve their pristine abundances and typically
do not migrate far beyond their birth environments over their short
lifetimes, in contrast to older stars like the Sun. They are also
unaffected by depletion onto dust grains, unlike the cold/warm
interstellar medium (ISM) or HII regions.
A carefully selected sample of early B-type stars in OB associations
and the field within the solar neighbourhood is studied
comprehensively. Quantitative spectroscopy is used to characterise
their atmospheric properties in a self-consistent way. Present-day
abundances for the astrophysically most interesting chemical elements
are derived in order to investigate whether a present-day cosmic
abundance standard can be established.
Description:
Stellar parameters and elemental abundances for a sample of 20
sharp-lined early B-type stars in the solar vicinity are presented.
High-resolution and high-S/N FOCES, FEROS and ELODIE spectra were
investigated using sophisticated non-LTE modelling and a comprehensive
analysis methodology. Independent indicators like multiple ionization
equilibria, the Stark-broadened hydrogen Balmer line profiles and
large numbers of helium and metal lines were reproduced
simultaneously. Precise and accurate data on effective temperatures,
surface gravities, microturbulent, macroturbulent and projected
rotational velocities, color excesses, intrinsic V magnitudes,
evolutionary masses, spectroscopic distances and distances from
Hipparcos parallaxes, and elemental abundances for carbon, nitrogen,
oxygen, neon, magnesium, silicon and iron are summarised in the
tables.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table5.dat 98 20 Stellar parameters for the sample stars
table6.dat 109 20 Metal abundances for the sample stars
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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- 2 I2 --- Seq Sequential number
4- 11 A8 --- Name Object name
14- 18 I5 K Teff Effective temperature
20- 22 I3 K e_Teff Mean error on effective temperature
25- 28 F4.2 [cm/s2] logg Surface gravity
30- 33 F4.2 [cm/s2] e_logg Mean error on surface gravity
36 I1 km/s xi Microturbulent velocity
38 I1 km/s e_xi Mean error on microturbulent velocity
41- 42 I2 km/s vsini Projected rotational velocity
44 I1 km/s e_vsini Mean error on projected rotational velocity
47- 48 I2 km/s zeta ? radial-tangential macroturbulent velocity
50 I1 km/s e_zeta ? Mean error on macroturbulent velocity
53- 56 F4.2 mag E(B-V) Colour excess
58- 61 F4.2 mag e_E(B-V) Mean error on colour excess
64- 67 F4.2 mag Vmag0 Intrinsic magnitude (apparent) in V filter
69- 72 F4.2 mag e_Vmag0 Mean error on intrinsic V magnitude
75- 78 F4.1 solMass Mevol Evolutionary Mass
80- 82 F3.1 solMass e_Mevol Mean error on evolutionary mass
85- 87 I3 pc dists Spectroscopic distance
89- 90 I2 pc e_dists Mean error on spectroscopic distances
93- 95 I3 pc distH ? Hipparcos distance
97- 98 I2 pc e_distH ? Mean error on Hipparcos distance
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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- 2 I2 --- Seq Sequential number
4- 11 A8 --- Name Object name
14- 17 F4.2 [---] C Carbon abundance (1)
19- 22 F4.2 [---] e_C Mean error on C abundance
24- 25 I2 --- o_C Number of lines analysed for C abundance
28- 31 F4.2 [---] N Nitrogen abundance (1)
33- 36 F4.2 [---] e_N Mean error on N abundance
38- 39 I2 --- o_N Number of lines analysed for N abundance
42- 45 F4.2 [---] O Oxygen abundance (1)
47- 50 F4.2 [---] e_O Mean error on O abundance
52- 53 I2 --- o_O Number of lines analysed for O abundance
56- 59 F4.2 [---] Ne Neon abundance (1)
61- 64 F4.2 [---] e_Ne Mean error on Ne abundance
66- 67 I2 --- o_Ne Number of lines analysed for Ne abundance
70- 73 F4.2 [---] Mg Magnesium abundance (1)
75- 78 F4.2 [---] e_Mg ? Mean error on Mg abundance
80- 81 I2 --- o_Mg Number of lines analysed for Mg abundance
84- 87 F4.2 [---] Si Silicon abundance (1)
89- 92 F4.2 [---] e_Si Mean error on Si abundance
94- 95 I2 --- o_Si ? Number of lines analysed for Si abundance
98-101 F4.2 [---] Fe Iron abundance (1)
103-106 F4.2 [---] e_Fe Mean error on Fe abundance
108-109 I2 --- o_Fe Number of lines analysed for Fe abundance
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Note (1): Abundances are presented on the scale 12+log[X/H].
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Acknowledgements:
Maria-Fernanda Nieva, nieva(at)sternwarte.uni-erlangen.de
(End) N. Przybilla [Univ. Erlangen-Nuremberg], P. Vannier [CDS] 23-Jan-2012