Oxygen abundances in G- and F-type stars from HARPS

We present a detailed and uniform study of oxygen abundance from two different oxygen lines at 6158$\AA$ and 6300$\AA$ in a large sample of solar-type stars. The results are used to check the behaviour of these spectral lines as oxygen abundance indicators and to study the evolution of oxygen in thick and thin disk populations of the Galaxy. Equivalent width measurements were carried out for the [OI]~6158$\AA$ and OI~6300$\AA$ lines. LTE abundances were obtained from these two lines in 610 and 535 stars, respectively. We were able to measure oxygen abundance from both indicators in 447 stars, enabling us, for the first time, to compare them in a uniform way. Careful error analysis has been performed. We found that oxygen abundances derived from the 6158$\AA$ and 6300$\AA$ lines agree to within 0.1dex in 58\% of the stars in our sample, and this result improves for higher signal-to-noise values. We confirm an oxygen enhancement in stars of the thick disk, as has also been seen for other $\alpha$-elements. The new oxygen abundances confirm previous findings for a progressive linear rise in the oxygen-to-iron ratio with a slope equal to 0.78 from solar metallicity to [Fe/H]$\sim$-1. However, the slope we measured is steeper than the one found in previous studies based on the oxygen triplet. Below [Fe/H]=$-$0.6 our stars show [O/Fe] ratios as high as $\sim$0.8, which can be interpreted as evidence for oxygen overproduction in the Galactic thick disk. These high oxygen abundances do not pose a problem to chemodynamical models since there is a range of parameters that can accommodate our results.

[1]  D. F. Gray,et al.  The Observation and Analysis of Stellar Photospheres , 2021 .

[2]  A. Helmi,et al.  MORE PIECES OF THE PUZZLE: CHEMISTRY AND SUBSTRUCTURES IN THE GALACTIC THICK DISK , 2014, 1407.2533.

[3]  W. Schuster,et al.  Carbon and oxygen abundances in stellar populations , 2014, 1406.5218.

[4]  J. Navarro,et al.  THE EFFECT OF RADIAL MIGRATION ON GALACTIC DISKS , 2014, 1405.3317.

[5]  M. Martig,et al.  Dissecting simulated disc galaxies - I. The structure of mono-age populations , 2014, 1405.1726.

[6]  R. Rebolo,et al.  Li depletion in solar analogues with exoplanets - Extending the sample , 2013, 1311.6414.

[7]  D. O. Astronomy,et al.  Exploring the Milky Way stellar disk - A detailed elemental abundance study of 714 F and G dwarf stars in the solar neighbourhood , 2013, 1309.2631.

[8]  M. Tsantaki,et al.  SWEET-Cat: A catalogue of parameters for Stars With ExoplanETs - I. New atmospheric parameters and masses for 48 stars with planets , 2013, 1307.0354.

[9]  M. Tsantaki,et al.  Deriving precise parameters for cool solar-type stars Optimizing the iron line list ?;??;??? , 2013, 1304.6639.

[10]  A. Robin,et al.  Kinematics and chemical properties of the Galactic stellar populations - The HARPS FGK dwarfs sample , 2013, 1304.2561.

[11]  K. Cunha,et al.  CARBON AND OXYGEN ABUNDANCES IN THE HOT JUPITER EXOPLANET HOST STAR XO-2B AND ITS BINARY COMPANION , 2013, 1304.0395.

[12]  L. Mashonkina,et al.  Influence of departures from LTE on oxygen abundance determination in the atmospheres of A-K stars , 2013, 1302.1048.

[13]  C. Prieto,et al.  OXYGEN ABUNDANCES IN NEARBY FGK STARS AND THE GALACTIC CHEMICAL EVOLUTION OF THE LOCAL DISK AND HALO , 2013, 1301.1582.

[14]  C. Chiappini,et al.  Chemodynamical evolution of the Milky Way disk - I. The solar vicinity , 2012, 1208.1506.

[15]  V. Adibekyan,et al.  Chemical abundances of 1111 FGK stars from the HARPS GTO planet search program - Galactic stellar populations and planets , 2012, 1207.2388.

[16]  M. Martig,et al.  Radial migration does little for Galactic disc thickening , 2012, 1205.6475.

[17]  M. Krumholz,et al.  EVOLVING GRAVITATIONALLY UNSTABLE DISKS OVER COSMIC TIME: IMPLICATIONS FOR THICK DISK FORMATION , 2011, 1112.1410.

[18]  V. Adibekyan,et al.  A new α-enhanced super-solar metallicity population , 2011, 1111.4936.

[19]  Ann Merchant Boesgaard,et al.  BERYLLIUM AND ALPHA-ELEMENT ABUNDANCES IN A LARGE SAMPLE OF METAL-POOR STARS , 2011, 1110.2823.

[20]  Instituto de Astrof'isica de Canarias,et al.  Spectroscopic stellar parameters for 582 FGK stars in the HARPS volume-limited sample. Revising the metallicity-planet correlation , 2011, 1108.5279.

[21]  G. Marcy,et al.  CARBON AND OXYGEN IN NEARBY STARS: KEYS TO PROTOPLANETARY DISK CHEMISTRY , 2011, 1106.5449.

[22]  Instituto de Astrof'isica de Canarias,et al.  Spectroscopic characterization of a sample of metal-poor solar-type stars from the HARPS planet search program , 2010, 1012.1528.

[23]  F. Bouchy,et al.  The HARPS search for southern extrasolar planets - XXV. Results from the metal-poor sample , 2010, 1011.2094.

[24]  N. Santos,et al.  CHEMICAL CLUES ON THE FORMATION OF PLANETARY SYSTEMS: C/O VERSUS Mg/Si FOR HARPS GTO SAMPLE , 2010, Proceedings of the International Astronomical Union.

[25]  M. Martig,et al.  THE THICK DISKS OF SPIRAL GALAXIES AS RELICS FROM GAS-RICH, TURBULENT, CLUMPY DISKS AT HIGH REDSHIFT , 2009, 0910.3677.

[26]  M. Asplund,et al.  The chemical composition of the Sun , 2009, 0909.0948.

[27]  J. Binney,et al.  Origin and structure of the Galactic disc(s) , 2009, 0907.1899.

[28]  D. Fabbian,et al.  Neutral oxygen spectral line formation revisited with new collisional data: large departures from LTE at low metallicity , 2009, 0902.4472.

[29]  N. Santos,et al.  Chemical abundances of 451 stars from the HARPS GTO planet search program - Thin disc, thick disc, and planets , 2009, 0902.3374.

[30]  A. Maeder.  Physics, Formation and Evolution of Rotating Stars , 2009 .

[31]  T. Ayres.  Solar Forbidden Oxygen, Revisited , 2008 .

[32]  D. Queloz,et al.  Spectroscopic parameters for 451 stars in the HARPS GTO planet search program - Stellar [Fe/H] and the frequency of exo-Neptunes , 2008, 0805.4826.

[33]  A. Helmi,et al.  Simulations of minor mergers - I. General properties of thick discs , 2008, 0803.2323.

[34]  A. Norton,et al.  The Solar Oxygen Crisis: Probably Not the Last Word , 2007, astro-ph/0702162.

[35]  C. Prieto,et al.  Oxygen abundances in nearby stars - Clues to the formation and evolution of the Galactic disk , 2007, astro-ph/0701362.

[36]  Observatoire de Geneve,et al.  Oxygen abundances in planet-harbouring stars. Comparison of different abundance indicators , 2005, astro-ph/0509326.

[37]  J. Valenti,et al.  Spectroscopic Properties of Cool Stars (SPOCS). I. 1040 F, G, and K Dwarfs from Keck, Lick, and AAT Planet Search Programs , 2005 .

[38]  S. Honda,et al.  Photospheric CNO Abundances of Solar-Type Stars , 2005 .

[39]  Matthias Steinmetz,et al.  Accretion relics in the solar neighbourhood : Debris from ωCen's parent galaxy , 2004, astro-ph/0408567.

[40]  R. Rebolo,et al.  Oxygen and magnesium abundance in the ultra-metal-poor giants CS 22949-037 and CS 29498-043: Challenges in models of atmospheres , 2004, astro-ph/0403033.

[41]  C. Prieto,et al.  Line formation in solar granulation IV. (O I), O I and OH lines and the photospheric O abundance , 2003, astro-ph/0312290.

[42]  Jean-Luis Lizon,et al.  Setting New Standards with HARPS , 2003 .

[43]  S. Feltzing,et al.  Oxygen trends in the Galactic thin and thick disks , 2003, astro-ph/0310741.

[44]  Jennifer A. Johnson,et al.  Oxygen Abundances in Metal-poor Stars , 2003, astro-ph/0307063.

[45]  S. Johansson,et al.  Experimental f-Value and Isotopic Structure for the Ni I Line Blended with [O I] at 6300 Å , 2003, astro-ph/0301382.

[46]  M. Steinmetz,et al.  Simulations of Galaxy Formation in a Λ Cold Dark Matter Universe. II. The Fine Structure of Simulated Galactic Disks , 2002, astro-ph/0212282.

[47]  A. Mezzacappa,et al.  Nucleosynthesis and Stellar Evolution , 2002 .

[48]  M. Asplund,et al.  O/Fe in metal-poor main sequence and subgiant stars ? , 2002, astro-ph/0205372.

[49]  Carlos Allende Prieto,et al.  The Forbidden Abundance of Oxygen in the Sun , 2001, astro-ph/0106360.

[50]  Y. Takeda.  Oxygen line formation in late-F through early-K disk/halo stars. Infrared O I triplet and [O I] lines , 2001, astro-ph/0105215.

[51]  C. Chiappini,et al.  Abundance Gradients and the Formation of the Milky Way , 2001, astro-ph/0102134.

[52]  P. Bonifacio,et al.  Oxygen in the Very Early Galaxy , 2001, astro-ph/0101032.

[53]  J. Prochaska,et al.  The Galactic Thick Disk Stellar Abundances , 2000, astro-ph/0008075.

[54]  R. Ramaty,et al.  Light-Element Evolution and Cosmic-Ray Energetics , 1999, astro-ph/9909021.

[55]  G. Israelian,et al.  Oxygen Abundances in Unevolved Metal-poor Stars from Near-Ultraviolet OH Lines , 1998, astro-ph/9806235.

[56]  S. Woosley,et al.  The Evolution and Explosion of Massive Stars. II. Explosive Hydrodynamics and Nucleosynthesis , 1995 .

[57]  P. Quinn,et al.  Heating of galactic disks by mergers , 1993 .

[58]  Ingemar Furenlid,et al.  Solar flux atlas from 296 to 1300 nm , 1985 .

[59]  Ralph C. Bohlin,et al.  A survey of ultraviolet interstellar absorption lines , 1983 .

[60]  D. Lambert.  The abundances of the elements in the solar photosphere – VIII. Revised abundances of carbon, nitrogen and oxygen , 1978 .

[61]  H. Drawin.  Zur formelmäßigen Darstellung des Ionisierungsquerschnitts für den Atom-Atomstoß und über die Ionen-Elektronen-Rekombination im dichten Neutralgas , 1968 .

[62]  P. Bonifacio,et al.  The photospheric solar oxygen project. I. Abundance analysis of atomic lines and influence of atmosp , 2008, 0805.4398.

[63]  S. Vogt,et al.  Oxygen in Unevolved Metal-Poor Stars from Keck Ultraviolet HIRES Spectra , 1999 .

[64]  Masa-Aki Hashimoto,et al.  Core-Collapse Supernovae and Their Ejecta , 1995 .

[65]  R. Kurucz.  ATLAS9 Stellar Atmosphere Programs and 2 km/s grid. , 1993 .

[66]  N. Grevesse,et al.  Abundances of the elements: Meteoritic and solar , 1989 .

[67]  J. Wheeler,et al.  Abundance Ratios as a Function of Metallicity , 1989 .