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J/A+A/300/751       Metal-poor stars spectroscopy. II              (Axer+, 1995)

Spectroscopic analyses of metal-poor stars. II. The evolutionary stage of subdwarfs. AXER M., FUHRMANN K., GEHREN T. <Astron. Astrophys. 300, 751 (1995)> =1995A&A...300..751A (SIMBAD/NED BibCode)
ADC_Keywords: Stars, metal-deficient; Stars, masses; Stars, distances Keywords: stars: distances - stars: evolution - stars: fundamental parameters - stars: kinematics - stars: subdwarfs Description: Models of post-main sequence stellar evolution of VandenBerg & Bell have been applied to determine spectroscopic masses and distances for metal-poor stars. Careful consideration of the most important error sources published in more recent papers such as VandenBerg for the first time allow us to draw firm statistical conclusions. It is shown that the evolutionary calculations qualitatively fit to the observed stellar parameters whereas quantitatively they predict too high ages for metal-poor stars. As an important result we confirm that evolutionary sequences need to be calibrated with respect to their metal abundance in order to use their absolute predictions of temperature and luminosity. In our spectroscopic analyses the strong dependence between surface gravity and abundances determined from Fe I lines restricts the accuracy of Fe abundances in subgiants to 0.1 dex at best. The most remarkable result of our evolutionary and kinematic investigations of halo stars refers to the large fraction of slightly evolved subgiants among the so-called subdwarfs. Since conventional photometric approaches often assume that the great majority of metal-poor stars are dwarfs this results in distances that are systematically too low for their samples. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1 87 115 Fundamental stellar parameters of the program stars table3 124 115 Stellar parameters derived from spectroscopy assuming LTE table4 114 115 Stellar parameters derived from spectroscopy including non-LTE corrections table5 101 115 Galactic velocities
Byte-by-byte Description of file: table1
Bytes Format Units Label Explanations
1- 10 A10 --- HD HD number 12- 20 A9 --- G Giclas number 22- 32 A11 --- Name Other name 34- 37 I4 K Teff Effective temperature for LTE assumption 39- 42 F4.2 [cm/s2] logg1 Surface gravity for LTE assumption 46- 50 F5.2 [Sun] [Fe/H]1 Metallicity for LTE assumption 53- 55 A3 --- Class Subdivision in three classes of LTE assumption 58- 61 F4.2 [cm/s2] Dlogg Non-LTE correction in logg 63- 66 F4.2 [Sun] D[Fe/H] non-LTE correction in [Fe/H] 68- 71 F4.2 [cm/s2] logg2 Surface gravity for non-LTE assumption 73- 76 F4.2 [cm/s2] e_logg1 rms uncertainty on log g1 (LTE value) 78- 82 F5.2 [Sun] [Fe/H]2 Metallicity for non-LTE assumption 84- 87 F4.2 [Sun] e_[Fe/H]1 rms uncertainty on [Fe/H]1 (LTE value)
Byte-by-byte Description of file: table3, table4
Bytes Format Units Label Explanations
1- 10 A10 --- HD Hd number 13- 20 A8 --- G Giclas number 22- 32 A11 --- Name Other name 36- 42 F7.4 [K] D(log(Teff)) Temperature corrections necessary for individual adjustment to the metal abundance 44- 48 F5.2 mag BC Bolometric correction 52- 55 F4.2 solMass Mass Mass 58- 61 F4.2 solMass e_Mass rms uncertainty on Mass 63- 68 F6.4 arcsec plx Spectroscopic parallax 70- 75 F6.4 arcsec e_plx rms uncertainty on plx 77- 79 I3 pc Dist Distance 82- 84 I3 pc e_Dist rms uncertainty on distance 86- 90 F5.2 mag MV Absolute visual magnitude 92- 95 F4.2 mag e_MV rms uncertainty on MV 97-101 F5.2 mag Mbol Bolometric magnitude 103-106 F4.2 mag e_Mbol rms uncertainty on Mbol
Byte-by-byte Description of file: table5
Bytes Format Units Label Explanations
1- 10 A10 --- HD HD number 13- 20 A8 --- G Giclas number 22- 32 A11 --- Name Other name 34- 37 I4 km/s RV Radial velocity 39- 44 F6.4 s/yr pmRA proper motion in right ascension 46- 51 F6.3 arcsec/yr pmDE Proper motion in declination 53- 56 I4 km/s U1 U velocity for LTE assumption 58- 61 I4 km/s V1 V velocity for LTE assumption 63- 66 I4 km/s W1 W velocity for LTE assumption 68- 71 I4 km/s Vgal1 Galactic velocity for LTE assumption 74- 76 I3 km/s e_Vgal1 rms uncertainty on Vgal1 78- 81 I4 km/s U2 U velocity for non-LTE assumption 83- 86 I4 km/s V2 V velocity for non-LTE assumption 88- 91 I4 km/s W2 W velocity for non-LTE assumption 93- 96 I4 km/s Vgal2 Galactic velocity for non-LTE assumption 99-101 I3 km/s e_Vgal2 rms uncertainty on Vgal2

(End) Patricia Bauer [CDS] 05-Jan-1995
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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