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J/ApJ/527/879    Gravities for late-type stars (Allende Prieto+, 1999)

A consistency test of spectroscopic gravities for late-type stars Allende Prieto C., Garcia Lopez R.J., Lambert D.L., Gustafsson B. <Astrophys. J. 527, 879 (1999)> =1999ApJ...527..879A
ADC_Keywords: Abundances, [Fe/H] ; Models, atmosphere ; Stars, late-type ; Parallaxes, trigonometric ; Stars, late-type Keywords: stars: abundances - stars: atmospheres - stars: fundamental parameters - stars: late-type Abstract: Chemical analyses of late-type stars are usually carried out following the classical recipe: LTE line formation and homogeneous, plane-parallel, flux-constant, and LTE model atmospheres. We review different results in the literature that have suggested significant inconsistencies in the spectroscopic analyses, pointing out the difficulties in deriving independent estimates of the stellar fundamental parameters and hence, detecting systematic errors. The trigonometric parallaxes measured by the Hipparcos mission provide accurate appraisals of the stellar surface gravity for nearby stars, which are used here to check the gravities obtained from the photospheric iron ionization balance. We find an approximate agreement for stars in the metallicity range -1.0≲[Fe/H]≲0, but the comparison shows that the differences between the spectroscopic and trigonometric gravities decrease toward lower metallicities for more metal-deficient dwarfs (-2.5≲[Fe/H]≲-1.0), which casts a shadow upon the abundance analyses for extreme metal-poor stars that make use of the ionization equilibrium to constrain the gravity. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 104 243 Data for the Stars in the Comparison
See also: I/239 : The Hipparcos and Tycho Catalogues (ESA 1997) Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 12 A12 --- Name Star Name 15- 19 F5.2 [Sun] [Fe/H] Log Iron to Hydrogen abundance ratio 23- 27 F5.2 solMass Mass Mass of the star in solar masses 31- 35 F5.2 mag Vmag V band magnitude 39- 43 F5.2 mag VMag Absolute V band magnitude 48- 51 I4 K Teff Effective temperature 54- 58 F5.2 [cm/s2] HLogG Log surface gravity from HIPPARCOS 62- 66 F5.2 [cm/s2] SLogG Log surface gravity from spectroscopic measurements 70- 75 F6.2 mas Plx Parallax of the star 78- 81 F4.2 mas e_Plx Error in Para 84 A1 --- r_Name Reference code number (1) 86 A1 --- f_Name Isochrone reference code number (2) 89-104 A16 --- CCDM Components name of double and multiple stars from Dommanget & Nys Cat. I/211
Note (1): 0 = Gratton et al. (1997A&A...314..191G) 1 = Edvardsson (1998A&A...190..148E) 2 = Bonnell & Bell (1993MNRAS.264..334B) 3 = Fuhrmann et al. (1997A&A...323..909F) 4 = Magain (1989A&A...305..245M) 5 = Ryan, Norris & Beers (1996ApJ...471..254R) Note (2): 0 = within the metallicity range of Bergbusch & Vandenberg (1992ApJS...81..163B) 1 = [Fe/H] too low ([Fe/H] = -2.26 is assumed in the grid of Bergbusch & Vandenberg (1992) or [Fe/H] too high ([Fe/H] = -0.47 is used)
History: From ApJ electronic edition
(End) Greg Schwarz [AAS] 17-Mar-2000
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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