J/A+A/ ================================================================================ S4N: A Spectroscopic Survey of Stars in the Solar Neighborhood Allende Prieto, C., Barklem, P. S., Lambert, D. L., Cunha, K. ================================================================================ ADC_Keywords: Keywords: Surveys - Stars - Stars: fundamental parameters - Stars: abundances - Galaxy: solar neighbourhood Abstract: We report the results of a high-resolution spectroscopic survey of all the stars more luminous than M_V = 6.5 mag within 14.5 pc from the Sun. The Hipparcos catalog's completeness limits guarantee that our survey is comprehensive and free from some of the selection effects in other samples of nearby stars. The resulting spectroscopic database, which we have made publicly available, includes spectra for 118 stars obtained with a resolving power of R ~ 50,000, continuous spectral coverage between ~ 362-921 nm, and typical signal-to-noise ratios in the range 150-600. We derive stellar parameters and perform a preliminary abundance and kinematic analysis of the F-G-K stars in the sample. The inferred metallicity ([Fe/H]) distribution is centered at about -0.1 dex, and shows a standard deviation of 0.2 dex. A comparison with larger samples of Hipparcos stars, some of which have been part of previous abundance studies, suggests that our limited sample is representative of a larger volume of the local thin disk. We identify a number of metal-rich K-type stars which appear to be very old, confirming the claims for the existence of such stars in the solar neighborhood. With atmospheric effective temperatures and gravities derived independently of the spectra, we find that our classical LTE model-atmosphere analysis of metal-rich (and mainly K-type) stars provides discrepant abundances from neutral and ionized lines of several metals. This ionization imbalance could be a sign of departures from LTE or inhomogeneous structure, which are ignored in the interpretation of the spectra. Alternatively, but seemingly unlikely, the mismatch could be explained by systematic errors in the scale of effective temperatures. Based on transitions of majority species, we discuss abundances of 16 chemical elements. In agreement with earlier studies we find that the abundance ratios to iron of Si, Sc, Ti, Co, and Zn become smaller as the iron abundance increases until approaching the solar values, but the trends reverse for higher iron abundances. At any given metallicity, stars with a low galactic rotational velocity tend to have high abundances of Mg, Si, Ca, Sc, Ti, Co, Zn, and Eu, but low abundances of Ba, Ce, and Nd. The Sun appears deficient by roughly 0.1 dex in O, Si, Ca, Sc, Ti, Y, Ce, Nd, and Eu, compared to its immediate neighbors with similar iron abundances. Description: Tables with kinematic data and chemical abundances for the sample. The atomic line data are also provided. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table5.dat 249 118 Kinematics table6.dat 62 275 Atomic line data table7.dat 471 118 Chemical abundances -------------------------------------------------------------------------------- Byte-by-byte Description of file: table5.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 12 I12 --- HIP Hipparcos number 18- 25 F8.4 deg RA Right ascension (ICRS J1991.25) 31- 38 F8.4 deg DEC Declination (ICRS J1991.25) 44- 51 F8.4 mas Plx Trigonometric parallax 55- 64 F10.4 mas/yr pmRA Proper motion in RA * cos(DEC) 68- 77 F10.4 mas/yr pmDEC Proper motion in DE 81- 90 F10.4 km/s vr Radial velocity 94-103 F10.4 km/s U U galactic velocity 107-116 F10.4 km/s V V galactic velocity 120-129 F10.4 km/s W W galactic velocity 134-144 E11.5 deg e_RA Uncertainty in RA 149-159 E11.5 deg e_DEC Uncertainty in DEC 165-171 F7.4 mas e_Plx Uncertainty in Plx 178-184 F7.4 mas e_pmRA Uncertainty in pmRA 191-197 F7.4 mas e_pmDEC Uncertainty in pmDEC 201-210 F10.4 km/s e_vr Uncertainty in vr 214-223 F10.4 km/s e_U Uncertainty in U 227-236 F10.4 km/s e_V Uncertainty in V 240-249 F10.4 km/s e_W Uncertainty in W -------------------------------------------------------------------------------- Byte-by-byte Description of file: table6.dat ----------------------------------------------------------------------------- Bytes Format Units Label Explanations ----------------------------------------------------------------------------- 1- 3 I3 --- index Index 6- 7 I2 --- Z Atomic number 10- 10 I1 --- ion Ionization stage (1=neutral, 2=singly ionized) 14- 23 F10.4 Angströms Wavel Central wavelength 27- 31 F5.3 eV E.P. Lower excitation potential 34- 39 F6.3 --- log(gf) Decimal logarithm of the product (g*f) 41- 45 F5.0 2.80e-21 m2 sigma H-collision broadening cross-section in atomic units (1) 47- 51 F5.3 --- alpha Velocity parameter alpha 54- 62 E9.3 rad s-1 Gammarad FWHM for Natural broadening (2) -------------------------------------------------------------------------------- NOTE (1): When sigma set to unity and alpha to zero, Ünsold's approximation is used. NOTE (2): When set to unity, natural broadening is neglected -------------------------------------------------------------------------------- Byte-by-byte Description of file: table7.dat ----------------------------------------------------------------------------- Bytes Format Units Label Explanations ----------------------------------------------------------------------------- 1- 12 I12 --- HIP Hipparcos number 14- 21 F8.2 dex C [C/H] (1) 23- 30 F8.2 dex O [O/H] 32- 39 F8.2 dex Mg [Mg/H] 41- 48 F8.2 dex Si [Si/H] 50- 57 F8.2 dex Ca [Ca/H] 59- 66 F8.2 dex Sc [Sc/H] 68- 75 F8.2 dex Ti [Ti/H] 77- 84 F8.2 dex Fe [Fe/H] 86- 93 F8.2 dex Co [Co/H] 95-102 F8.2 dex Ni [Ni/H] 104-111 F8.2 dex Cu [Cu/H] 113-120 F8.2 dex Zn [Zn/H] 122-129 F8.2 dex Y [Y/H] 131-138 F8.2 dex Ba [Ba/H] 140-147 F8.2 dex Ce [Ce/H] 149-156 F8.2 dex Nd [Nd/H] 158-165 F8.2 dex Eu [Eu/H] 167-174 F8.2 dex e(C) Internal uncertainty in [C/H] (2) 176-183 F8.2 dex e(O) Internal uncertainty in [O/H] 185-192 F8.2 dex e(Mg) Internal uncertainty in [Mg/H] 194-201 F8.2 dex e(Si) Internal uncertainty in [Si/H] 203-210 F8.2 dex e(Ca) Internal uncertainty in [Ca/H] 212-219 F8.2 dex e(Sc) Internal uncertainty in [Sc/H] 221-228 F8.2 dex e(Ti) Internal uncertainty in [Ti/H] 230-237 F8.2 dex e(Fe) Internal uncertainty in [Fe/H] 239-246 F8.2 dex e(Co) Internal uncertainty in [Co/H] 248-255 F8.2 dex e(Ni) Internal uncertainty in [Ni/H] 257-264 F8.2 dex e(Cu) Internal uncertainty in [Cu/H] 266-273 F8.2 dex e(Zn) Internal uncertainty in [Zn/H] 275-282 F8.2 dex e(Y) Internal uncertainty in [Y/H] 284-291 F8.2 dex e(Ba) Internal uncertainty in [Ba/H] 293-300 F8.2 dex e(Ce) Internal uncertainty in [Ce/H] 302-309 F8.2 dex e(Nd) Internal uncertainty in [Nd/H] 311-318 F8.2 dex e(Eu) Internal uncertainty in [Eu/H] 320-327 F8.2 dex D(C) Change in [C/H] (3) 329-336 F8.2 dex D(O) Change in [O/H] 338-345 F8.2 dex D(Mg) Change in [Mg/H] 347-354 F8.2 dex D(Si) Change in [Si/H] 356-363 F8.2 dex D(Ca) Change in [Ca/H] 365-372 F8.2 dex D(Sc) Change in [Sc/H] 374-381 F8.2 dex D(Ti) Change in [Ti/H] 383-390 F8.2 dex D(Fe) Change in [Fe/H] 392-399 F8.2 dex D(Co) Change in [Co/H] 401-408 F8.2 dex D(Ni) Change in [Ni/H] 410-417 F8.2 dex D(Cu) Change in [Cu/H] 419-426 F8.2 dex D(Zn) Change in [Zn/H] 428-435 F8.2 dex D(Y) Change in [Y/H] 437-444 F8.2 dex D(Ba) Change in [Ba/H] 446-453 F8.2 dex D(Ce) Change in [Ce/H] 455-462 F8.2 dex D(Nd) Change in [Nd/H] 464-471 F8.2 dex D(Eu) Change in [Eu/H] -------------------------------------------------------------------------------- NOTE (1): The bracket notation for the abundance of an element 'El' relative to the solar value is used throughout: [El/H] = log10 {N(El)/N(H)} - log10 {N(El)/N(H)}_SUN with N=number density. This is set to -1000.00 when the abundance is not available. NOTE (2): When more than one transition is used, e(El) corresponds to the standard deviation. It is set to zero when only one line was employed. A value of -98.99 flags an upper limit. A value -1000.00 indicates that the abundance is not available. NOTE (3): D(El) is the change in [El/H] when the effective temperature is increased by 3*sigma (see Tables 2-4 in the paper). ================================================================================ (End)