The chemical compositions of Galactic disc F and G dwarfs

By B. E. Reddy, J. Tomkin, D. Lambert, C. Allende Prieto. 2002

596 citations recorded by the source corpus.

Photospheric abundances are presented for 27 elements from carbon to europium in 181 F and G dwarfs from a differential local thermodynamic equilibrium (LTE) analysis of high-resolution and high signal-to-noise ratio spectra. Stellar effective temperatures (T eff) were adopted from an infrared flux method calibration of Stromgren photometry. Stellar surface gravities (g) were calculated from Hipparcos parallaxes and stellar evolutionary tracks. Adopted T eff and g values are in good agreement with spectroscopic estimates. Stellar ages were determined from evolutionary tracks. Stellar space motions (U , V , W ) and a Galactic potential were used to estimate Galactic orbital parameters. These show that the vast majority of the stars belong to the Galactic thin disc. Relative abundances expressed as (X/Fe) generally confirm previously published results. We give results for C, N, O, Na, Mg, Al, Si, S, K, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Sr, Y, Zr, Ba, Ce, Nd and Eu. The α elements - O, Mg, Si, Ca and Ti - show (α/Fe) to increase slightly with decreasing (Fe/H). Heavy elements with dominant contributions at solar metallicity from the s-process show (s/Fe) to decrease slightly with decreasing (Fe/H). Scatter in (X/Fe) at a fixed (Fe/H) is entirely attributable to the small measurement errors, after excluding the few thick disc stars and the s-process-enriched CH subgiants. Tight limits are set on 'cosmic' scatter. If a weak trend with (Fe/H) is taken into account, the composition of a thin disc star expressed as (X/Fe) is independent of the star's age and birthplace for elements contributed in different proportions by massive stars (Type II supernovae), exploding white dwarfs (Type Ia supernovae) and asymptotic red giant branch stars. By combining our sample with various published studies, comparisons between thin and thick disc stars are made. In this composite sample, thick disc stars are primarily identified by their V LSR in the range −40 to −100 km s −1 . These are very old stars with origins in the inner Galaxy and metallicities (Fe/H) −0.4. At the same (Fe/H), the sampled thin disc stars have V LSR ∼ 0k m s −1 , and are generally younger with a birthplace at about the Sun's Galactocentric distance. In the range −0.35 (Fe/H) −0.70, well represented by present thin and thick disc samples, (X/Fe) of the thick disc stars is greater than that of thin disc stars for Mg, Al, Si, Ca, Ti and Eu. (X/Fe) is very similar for the thin and thick disc for - notably - Na and iron-group elements. Barium ((Ba/Fe)) may be underabundant in thick relative to thin disc stars. These results extend previous ideas about composition differences between the thin and thick disc.

Subfields: Astronomy and Astrophysics

View Paper: https://www.semanticscholar.org/paper/8a3d927ac1f03c4e871e8f29e75bc8c730d8a3e4

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

Citations in the corpus

Radial mixing and the transition between the thick and thin Galactic discs (2008, methodology): “8(a) we display [α/Fe] and [Fe/H] values from the samples of Reddy et al. (2003, 2006), Bensby et al. (2005) and Gilli et al. (2006).”
Population Synthesis in the Blue. IV. Accurate Model Predictions for Lick Indices and UBV Colors in Single Stellar Populations (2007, background): “On one side, Shi et al. (2002) and Reddy et al. (2003) find carbon to be overabundant relative to iron in metal-poor stars and increasingly so with decreasing [Fe/H].”
Lithium abundances of the local thin disc stars (2004, background): “This correlation probably reflects the form of the age-metallicity relation displayed by the field stars (Edvardsson et al. 1993; Chen et al. 2000; Reddy et al. 2003).”
THE ABUNDANCES OF NEUTRON-CAPTURE SPECIES IN THE VERY METAL-POOR GLOBULAR CLUSTER M15: A UNIFORM ANALYSIS OF RED GIANT BRANCH AND RED HORIZONTAL BRANCH STARS (2011, unknown): “For this figure, halo and disk star data have been taken from these surveys: Fulbright (2000)(34), Reddy et al. (2003)(76), Cayrel et al. (2004)(20), Cohen et al. (2004)(22), Simmerer et al. (2004)(80), Barklem et al. (2005)(8), Reddy, Lambert & Allende Prieto (2006)(75), François et al.…”
Evolution of interstellar dust and stardust in the solar neighbourhood (2007, methodology): “…element abundances for F and G stars from the solar neighbourhood are shown with di ﬀ erent symbols for each of the sources (Akerman et al. 2004; Reddy et al. 2003; Soubiran et al. 2005; Melendez et al. 2002; Jonsell et al. 2005; Venn et al. 2004; Chen et al. 2000; Gratton et al. 1991; Ca ﬀ…”
Lithium depletion in solar-like stars: no planet connection (2010, methodology): “The adopted mean age and 1-σ Gaussian-like upper and lower limits were derived from the age probability distribution (e.g., Lachaume et al. 1999; Reddy et al. 2003).”
Neutron-Capture Elements in the Early Galaxy (2008, methodology): “For this figure the data have been taken only from large-sample surveys: Fulbright (2000); Reddy et al. (2003); Cayrel et al. (2004); Cohen et al. (2004); Simmerer et al. (2004); Barklem et al. (2005, red points); Reddy, Lambert & Allende Prieto (2006); François et al. (2007).”
The age structure of stellar populations in the solar vicinity Clues of a two-phase formation history of the Milky Way disk (2013, background): “Reddy et al. (2003) or Bensby & Feltzing (2012) proposed that the hiatus in metallicity between metal-rich thick disk objects (at [Fe/H] ∼ 0.0 dex) and thin disk metal-poor stars (at [Fe/H] ∼ −0.6 dex) was caused by accretion of lower metallicity gas which diluted the ISM at the end of the thick…”
The Rise of the s-Process in the Galaxy (2004, background): “…full picture of thick disk stellar abundances is still evolving, elemental abundance work so far indicates that high-mass stellar nucleosynthesis products are enhanced in thick disk stars relative to thin disk stars (Fuhrmann 1998; Prochaska et al. 2000; Reddy et al. 2003; Mashonkina et al. 2003).”
Abundance Variations within Globular Clusters (2004, result): “…SNEDEN CARRETTA Tomkin & Lambert (1995) (+0.3 ≥ [Fe/H] ≥ –0.9); Feltzing & Gustafsson (1998) (+0.5 ≥ [Fe/H] ≥ –0.1); Fulbright (2000) (0.0 ≥ [Fe/H] ≥ –3.0); Reddy et al. (2003) (+0.1 ≥ [Fe/H] ≥ –0.7); Gratton et al. (2003) (+0.1 ≥ [Fe/H] ≥ –2.6); and Simmerer et al. (2003) and J.A.…”
Measuring the vertical age structure of the Galactic disc using asteroseismology and SAGA (2015, background): “Thin disc stars are observed to be on average more metal-rich and less alpha-enhanced than thick disc stars (e.g. Edvardsson et al. 1993; Chen et al. 2000; Reddy et al. 2003; Fuhrmann 2008; Bensby, Feltzing & Oey 2014).”
alpha-, r-, and s-process element trends in the Galactic thin and thick disks (2004, methodology): “The reason for this difference lays in that we use an effective temperature that is 200 K lower than the one Reddy et al. (2003) use.”
The Galaxy in Context: Structural, Kinematic, and Integrated Properties (2016, background): “As expected, the thin disk stars follow nearcircular, corotational orbits with a low velocity dispersion (e.g., Edvardsson et al. 1993, Reddy et al. 2003).”
Chemical abundance analysis of the open clusters Cr 110, NGC 2099 (M 37), NGC 2420, NGC 7789, and M 67 (NGC 2682) (2009, methodology): “For the Milky Way field stars, we use the Thick and Thin Disc measurements from Reddy et al. (2003) and Reddy et al. (2006), who performed homeogeneous abundance calculations of a few hundred F/G dwarfs selected from th Hipparcos catalogue.”