OXYGEN ABUNDANCES IN NEARBY FGK STARS AND THE GALACTIC CHEMICAL EVOLUTION OF THE LOCAL DISK AND HALO

By I. Ramírez, C. Allende Prieto, D. Lambert. 2013

174 citations recorded by the source corpus.

Atmospheric parameters and oxygen abundances of 825 nearby FGK stars are derived using high-quality spectra and a non-local thermodynamic equilibrium analysis of the 777 nm O i triplet lines. We assign a kinematic probability for the stars to be thin-disk (P1), thick-disk (P2), and halo (P3) members. We confirm previous findings of enhanced [O/Fe] in thick-disk (P2 > 0.5) relative to thin-disk (P1 > 0.5) stars with [Fe/H] ≲ −0.2, as well as a “knee” that connects the mean [O/Fe]–[Fe/H] trend of thick-disk stars with that of thin-disk members at [Fe/H] ≳ −0.2. Nevertheless, we find that the kinematic membership criterion fails at separating perfectly the stars in the [O/Fe]–[Fe/H] plane, even when a very restrictive kinematic separation is employed. Stars with “intermediate” kinematics (P1 < 0.7, P2 < 0.7) do not all populate the region of the [O/Fe]–[Fe/H] plane intermediate between the mean thin-disk and thick-disk trends, but their distribution is not necessarily bimodal. Halo stars (P3 > 0.5) show a large star-to-star scatter in [O/Fe]–[Fe/H], but most of it is due to stars with Galactocentric rotational velocity V < −200 km s−1; halo stars with V > −200 km s−1 follow an [O/Fe]–[Fe/H] relation with almost no star-to-star scatter. Early mergers with satellite galaxies explain most of our observations, but the significant fraction of disk stars with “ambiguous” kinematics and abundances suggests that scattering by molecular clouds and radial migration have both played an important role in determining the kinematic and chemical properties of solar neighborhood stars.

Subfields: Astronomy and Astrophysics, Education, Instrumentation

View Paper: https://www.semanticscholar.org/paper/74ad1177f444288f67ad2b179787edb662f9bcaa

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

1. Volker Springel
2. L. Hernquist
3. Jo Bovy
4. Hans-Walter Rix
5. M. Vogelsberger
6. Shy Genel
7. P. Torrey
8. P. Hopkins

In Education

1. I. Minchev
2. C. Allende Prieto
3. T. Bensby
4. C. Chiappini
5. Sweden.
6. U. Michigan
7. J. Holtzman
8. M. Shetrone

In Instrumentation

1. L. Hernquist
2. Volker Springel
3. M. Vogelsberger
4. Shy Genel
5. P. Torrey
6. D. Nelson
7. I. Minchev
8. F. Marinacci

Citations in the corpus

• Chemodynamics of the Milky Way - I. The first year of APOGEE data (2013, result): “…the APOGEE and the HARPS sample there is no a-priori reason to expect the observed gap to be caused by selection biases, because unlike in SEGUE, RAVE or the highresolution studies of Bensby et al. (2003) and Ramírez et al. (2013), the thick disc was not targeted preferentially by these surveys.”
• Exploring the Milky Way stellar disk - A detailed elemental abundance study of 714 F and G dwarf stars in the solar neighbourhood (2013, background): “For example Ramírez et al. (2013), in their Fig.”
• CHEMICAL CARTOGRAPHY WITH APOGEE: METALLICITY DISTRIBUTION FUNCTIONS AND THE CHEMICAL STRUCTURE OF THE MILKY WAY DISK (2015, result): “These observations are similar to previous studies of the solar neighborhood (e.g., Adibekyan et al. 2012; Ramírez et al. 2013; Bensby et al. 2014; Nidever et al. 2014; Recio-Blanco et al. 2014), which also find two distinct sequences in the [α/Fe] versus [Fe/H] plane.”
• First results from the IllustrisTNG simulations: a tale of two elements - chemical evolution of magnesium and europium (2017, background): “…comparison to simulated abundance ratios based on star particles within a simulation, many effects including measurement errors, accurate atmospheric modeling, and observational completeness can influence the robustness of such a comparison (Wyse 1998; Ramírez et al. 2013; Nicholls et al. 2017).”
• The PASTEL catalogue: 2016 version (2016, background): “Since 2010, eleven papers have published more than 250 (Teff , log g, [Fe/H]) determinations, and four papers present more than 500 stars (Bensby et al. 2014; Luck 2014; Ramírez et al. 2013; Sousa et al. 2011).”
• SPECTRAL PROPERTIES OF COOL STARS: EXTENDED ABUNDANCE ANALYSIS OF 1,617 PLANET-SEARCH STARS (2016, methodology): “We modified our analysis procedure to set microturbulence according to the empirical formula of Ramirez et al. (2013) minus 0.22 km s−1 so that the value for the Sun matched the 0.85 km s−1 that we used to tune our line parameters.”