A Spectroscopic Study of the Ancient Milky Way: F- and G-Type Stars in the Third Data Release of the Sloan Digital Sky Survey

By C. Allende Prieto, Timothy C. Beers, R. Wilhelm, Heidi Jo Newberg, C. Rockosi, Brian Yanny, Y. S. Lee. 2005

301 citations recorded by the source corpus.

We perform an analysis of spectra and photometry for 22,770 stars included in the third data release (DR3) of the Sloan Digital Sky Survey (SDSS). We derive atmospheric parameters and distances. Our analysis procedures are throughly checked using three recently published spectroscopic libraries of nearby stars and alternative methods. The SDSS sample covers a range in stellar brightness of 14 < V < 22, primarily at intermediate Galactic latitudes, and comprises large numbers of F- and G-type stars from the thick-disk and halo populations, therefore including some of the oldest stars in the Milky Way. We find that halo stars exhibit a broad range of iron abundances, with a peak at [Fe/H] ≃ -1.4. This population exhibits essentially no Galactic rotation. Thick-disk G-dwarf stars at distances from the Galactic plane in the range 1 < |z| < 3 kpc show a much more compact metallicity distribution, with a maximum at [Fe/H] ≃ -0.7, and a median Galactic rotation lagging the local standard of rest by 63 km s-1. A comparison of color indices and metal abundances with isochrones indicates that no significant star formation has taken place in the halo in the last ~11 Gyr, but there are thick-disk stars that are at least 2 Gyr younger. We find the metallicities of thick-disk stars to be nearly independent of Galactocentric distance between 5 and 14 kpc from the Galactic center, in contrast with the marked gradients found in the literature for the thin disk. No vertical metallicity gradient is apparent for the thick disk, but we detect a gradient in its rotational velocity of -16 ± 4 km s-1 kpc-1 between 1 and 3 kpc from the plane. We estimate that among the stars in our sample there are over 2000 with an iron abundance [Fe/H] < -2, and over 150 stars with an iron abundance [Fe/H] < -3.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/2c9e694cd1fbd559d5f6b0b4df533ee5c4d77c1a

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In Astronomy and Astrophysics

1. D. Schneider
2. Hans-Walter Rix
3. Jo Bovy
4. J. Brinkmann
5. Simon D. M. White
6. C. Conroy
7. P. Hopkins
8. M. Blanton

In Instrumentation

1. Hans-Walter Rix
2. D. Schneider
3. Jo Bovy
4. J. Brinkmann
5. C. Conroy
6. I. Minchev
7. Simon D. M. White
8. M. Blanton

Citations in the corpus

• ASPCAP: THE APOGEE STELLAR PARAMETER AND CHEMICAL ABUNDANCES PIPELINE (2015, methodology): “Model fluxes need to be interpolated to evaluate fluxes at points off the grid nodes; the interpolation in fluxes is more accurate than interpolations of atmospheric structures (Mészáros & Allende Prieto 2013).”
• THE SEGUE STELLAR PARAMETER PIPELINE. I. DESCRIPTION AND COMPARISON OF INDIVIDUAL METHODS (2007, methodology): “The same grid described by Allende Prieto et al. (2006) is used by the SSPP.”
• THE SEGUE STELLAR PARAMETER PIPELINE. V. ESTIMATION OF ALPHA-ELEMENT ABUNDANCE RATIOS FROM LOW-RESOLUTION SDSS/SEGUE STELLAR SPECTRA (2010, methodology): “The SSPP estimates the atmospheric parameters via application of a number of approaches, such as a minimum distance method (Allende Prieto et al. 2006), neural network analysis (Bailer-Jones 2000; Willemsen et al. 2005; Re Fiorentin et al. 2007), auto-correlation analysis (Beers et al. 1999), and a…”
• Automatic determination of stellar atmospheric parameters and construction of stellar spectral templates of the Guoshoujing Telescope (LAMOST) (2011, methodology): “This paper is actually one of the series papers coming after Lee et al. (2008ab) and Allende Prieto et al. (2008).”
• CHEMICAL CARTOGRAPHY WITH APOGEE: LARGE-SCALE MEAN METALLICITY MAPS OF THE MILKY WAY DISK (2013, background): “Stars at larger distances from the plane have been observed to have flat or slightly positive radial metallicity gradients (Allende Prieto et al. 2006; Jurić et al. 2008; Carrell et al. 2012; Cheng et al. 2012b), as have older stars closer to the plane (Nordström et al. 2004).”
• METALLICITY GRADIENTS IN THE MILKY WAY DISK AS OBSERVED BY THE SEGUE SURVEY (2011, background): “REFERENCES Abadi, M. G., Navarro, J. F., Steinmetz, M., & Eke, V. R. 2003, ApJ, 597, 21 Abazajian, K. N., et al. 2009, ApJS, 182, 543 Aihara, H., et al. 2011, ApJS, 193, 29 Allende Prieto, C., Beers, T. C., Wilhelm, R., Newberg, H. J., Rockosi, C. M., Yanny, B., & Lee, Y. S. 2006, ApJ, 636, 804 An, ”
• J-PLUS: The Javalambre Photometric Local Universe Survey (2015, methodology): “Our analysis is based upon the FERRE code (Allende Prieto et al. 2006, and subsequent updates).”
• THE SEGUE STELLAR PARAMETER PIPELINE. II. VALIDATION WITH GALACTIC GLOBULAR AND OPEN CLUSTERS (2007, methodology): “The current techniques employed by the SSPP include a minimum distance method (Allende Prieto et al. 2006), neural network analysis (Bailer-Jones 2000; Willemsen et al. 2005; Re Fiorentin et al. 2007), autocorrelation analysis (Beers et al. 1999), and a variety of line index calculations based on pr”
• Stellar Abundance and Galactic Chemical Evolution through LAMOST Spectroscopic Survey (2006, methodology): “…of abundances and kinematics of stars in the various places of the thin and thick disks, such as the low-resolution spectroscopic survey of the stars situated at 0.5–5kpc from the Galactic plane (Gilmore et al. 2002) and the spectroscopic study based on SDSS survey (Allende Prieto et al. 2006).”
• SEGUE: A SPECTROSCOPIC SURVEY OF 240,000 STARS WITH g = 14–20 (2009, methodology): “C. Allende Prieto acknowledges support from NASA grants NAG 5-13057 and NAG 5- 13147.”
• Kinematics of SDSS subdwarfs: structure and substructure of the Milky Way halo (2009, methodology): “There has also been controversy in the literature with regards to the mean rotational velocity of the halo, with estimates of prograde (Chiba & Beers 2000; Kepley et al. 2007), no rotation (Gould & Popowski 1998; Allende Prieto et al. 2006), or retrograde (Majewski 1992).”
• THE METALLICITY DISTRIBUTION FUNCTIONS OF SEGUE G AND K DWARFS: CONSTRAINTS FOR DISK CHEMICAL EVOLUTION AND FORMATION (2011, methodology): “The target selection of their sample causes the MDF of Allende Prieto et al. (2006) to drop off steeply above [Fe/H] of −0.4; it may also cause the MDF to peak at around [Fe/H] of −0.7, more metal-poor than our MDF above |Z| of 1 kpc.”
• Dissecting simulated disc galaxies - I. The structure of mono-age populations (2014, background): “The Milky Way’s thick disc not only has a larger scale-height than the thin disc (Robin et al. 1996; Chen et al. 2001; Jurić et al. 2008), but it is also older, more metal-poor, and enhanced in alpha elements (Gilmore, Wyse, & Jones 1995; Fuhrmann 1998; Prochaska et al. 2000; Bensby et al. 2005; Red”
• Numerical simulation of a possible origin of the positive radial metallicity gradient of the thick disk (2013, background): “There is less certainty for vertical metallicity gradients with, on the one hand, Allende Prieto et al. (2006) finding no gradient and, on the other, Chen et al. (2011) finding a strongly negative gradient.”
• THE SEGUE STELLAR PARAMETER PIPELINE. IV. VALIDATION WITH AN EXTENDED SAMPLE OF GALACTIC GLOBULAR AND OPEN CLUSTERS (2010, unknown): “…− r Name Method g − r Name Method g − r T1 ki13 0.0 − 0.8 G1 ki13 0.0 − 0.8 M1 ki13 0.0 − 0.8 15 Section 4.1 T2 k24 0.0 − 0.8 G2 k24 0.0 − 0.8 M2 k24 0.0 − 0.8 15 Allende Prieto et al. (2006) T3 WBG −0.3 − 0.3∗ G3 WBG −0.3 − 0.3∗ M3 WBG −0.3 − 0.3∗ 10 Wilhelm et al. (1999) T4 ANNSR −0.3 − 0.8 G4…”