J/ApJ/797/13 Abundances of bright metal-poor stars (Schlaufman+, 2014)
The best and brightest metal-poor stars.
Schlaufman K.C., Casey A.R.
<Astrophys. J., 797, 13 (2014)>
=2014ApJ...797...13S 2014ApJ...797...13S (SIMBAD/NED BibCode)
ADC_Keywords: Milky Way ; Stars, metal-deficient ; Radial velocities ;
Abundances ; Photometry, infrared
Keywords: Galaxy: bulge; Galaxy: halo; Galaxy: stellar content; infrared: stars
stars: Population II; stars: statistics
Abstract:
The chemical abundances of large samples of extremely metal-poor (EMP)
stars can be used to investigate metal-free stellar populations,
supernovae, and nucleosynthesis as well as the formation and galactic
chemical evolution of the Milky Way and its progenitor halos. However,
current progress on the study of EMP stars is being limited by their
faint apparent magnitudes. The acquisition of high signal-to-noise
spectra for faint EMP stars requires a major telescope time
commitment, making the construction of large samples of EMP star
abundances prohibitively expensive. We have developed a new, efficient
selection that uses only public, all-sky APASS optical, 2MASS
near-infrared, and WISE mid-infrared photometry to identify bright
metal-poor star candidates through their lack of molecular absorption
near 4.6 microns.
Description:
As input to our sample selection, we use the APASS DR6 Catalog, the
2MASS All-Sky Point Source Catalog, and the AllWISE Source Catalog
(Henden+ 2012JAVSO..40..430H 2012JAVSO..40..430H; Skrutskie+ 2006AJ....131.1163S 2006AJ....131.1163S; Wright+
2010AJ....140.1868W 2010AJ....140.1868W; Mainzer+ 2011ApJ...731...53M 2011ApJ...731...53M).
We followed up our metal-poor star candidates with the Mayall
4m/Echelle, Gemini South/GMOS-S, and Magellan/MIKE telescopes and
spectrographs.
We observed 98 stars with the Mayall 4m/Echelle on 2013 June 25-27. We
observed 90 stars with Gemini South/GMOS-S in service mode from 2014
March to July (R∼3700). We observed 416 stars with Magellan/MIKE on
2014 June 21-23 and July 8-10 (R∼41000 in the blue and R∼35000 in the
red).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 96 90 Metal-poor candidate velocities and stellar parameters
for stars observed with Gemini South/GMOS-S
table2.dat 66 415 Metal-poor candidate velocities and stellar
parameters for stars observed with Magellan/MIKE
table3.dat 81 502 Metal-poor candidate star positions and photometry
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See also:
II/336 : AAVSO Photometric All Sky Survey (APASS) DR9 (Henden+, 2016)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
II/328 : AllWISE Data Release (Cutri+ 2013)
J/AJ/147/76 : M giant candidate photometry in the MW (Bochanski+, 2014)
J/ApJ/762/27 : Most metal-poor stars. III. [Fe/H]≤-3.0 stars (Yong+, 2013)
J/ApJ/762/26 : Most metal-poor stars. II. Galactic halo stars (Yong+, 2013)
J/ApJ/762/25 : The most metal-poor stars in HES and SDSS. I. (Norris+, 2013)
J/AJ/145/13 : Metal-poor stars from SDSS/SEGUE. I. Abundances (Aoki+, 2013)
J/AJ/142/188 : Metal-poor stars from the HES using CH G-band (Placco+, 2011)
J/ApJ/742/54 : CASH project II. Extremely metal-poor stars (Hollek+, 2011)
J/ApJ/724/341 : Nucleosynthesis of massive metal-free stars (Heger+, 2010)
J/ApJ/711/573 : Abundances in a halo stellar stream (Roederer+, 2010)
J/AJ/139/1051 : Carbon-enhanced metal-poor stars in the MW (Placco+, 2010)
J/ApJ/708/560 : Spectroscopy of UMa II and Coma Ber (Frebel+, 2010)
J/A+A/484/721 : HES survey IV. Candidate metal-poor stars (Christlieb+, 2008)
J/ApJ/660/1556 : Characterization of dusty debris disks (Rhee+, 2007)
J/ApJ/655/492 : Equivalent widths of 26 metal-poor stars (Aoki+, 2007)
J/ApJ/652/1585 : Bright metal-poor stars from HES survey (Frebel+, 2006)
J/A+A/416/1117 : Abundances in the early Galaxy (Cayrel+, 2004)
J/AJ/119/2866 : Proper motions of metal-poor stars (Beers+, 2000)
J/A+A/354/169 : Metal-poor field stars abundances (Gratton+, 2000)
J/AJ/103/1987 : Stars of very low metal abundance (Beers+ 1992)
J/AJ/100/1191 : Giants DDO photometry (Morrison+, 1990)
J/AJ/90/2089 : Stars of very low metal abundance. I (Beers+, 1985)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- 2MASS 2MASS identifier (JHHMMSS.ss+DDMMSS.s) (G1)
21- 26 F6.1 km/s RV [-223.6/231.2] Radial velocity
28- 31 F4.1 km/s E_RV [0.1/27.8] Upper limit error on RV
33- 36 F4.1 km/s e_RV [0.1/27.8] Lower limit error on RV
38- 41 I4 K Teff [3499/6760] Effective temperature
43- 45 I3 K E_Teff [9/120] Upper limit error on Teff
47- 49 I3 K e_Teff [7/205] Lower limit error on Teff
51- 54 F4.2 [cm/s2] logg [1.64/4.8] log10 of the surface gravity
56- 59 F4.2 [cm/s2] E_logg [0.02/0.99] Upper limit error on logg
61- 64 F4.2 [cm/s2] e_logg [0.01/1.93] Lower limit error on logg
66- 70 F5.2 [Sun] [Fe/H] [-2.77/0.77] Metallicity
72- 75 F4.2 [Sun] E_[Fe/H] [0.01/0.18] Upper limit error on [Fe/H]
77- 80 F4.2 [Sun] e_[Fe/H] [0.01/1.8] Lower limit error on [Fe/H]
82- 86 F5.2 [Sun] [a/Fe] [-0.09/0.55] Abundance [α/Fe]
88- 91 F4.2 [Sun] E_[a/Fe] [0/0.27] Upper limit error on [a/Fe]
93- 96 F4.2 [Sun] e_[a/Fe] [0.01/0.36] Lower limit error on [a/Fe]
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Byte-by-byte Description of file:table2.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- 2MASS 2MASS identifier (JHHMMSS.ss+DDMMSS.s) (G1)
21- 26 F6.1 km/s RV [-316.5/360.5]? Velocity
28 A1 --- u_Teff [:] Uncertainty flag on Teff
29- 32 I4 K Teff [4350/6740]? Effective temperature (1)
34 A1 --- u_log(g) [:] Uncertainty flag on log(g)
35- 38 F4.2 [cm/s2] log(g) [0.35/5]? Log of the surface gravity (1)
40 A1 --- u_[Fe/H] [:] Uncertainty flag on [Fe/H]
41- 45 F5.2 [-] [Fe/H] [-3.07/0.5]? Metallicity (1)
47 A1 --- u_xi [:] Uncertainty flag on xi
48- 51 F4.2 km/s xi [0.2/7.1]? Turbulent velocity ξ (1)
53- 57 F5.2 [-] [C/Fe] [-0.56/0.39]? Log of the carbon to iron
number abundance
59- 60 A2 --- Sel [v1/v2] Selection (2)
62- 66 A5 --- Notes Additional note(s) (3)
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Note (1): Given the spectral resolution and S/N of our sample, the uncertainties
in stellar parameters for the Magellan/MIKE sample are conservatively
estimated to be of order 100K in Teff, 0.2 in log(g), 0.1 in [Fe/H],
and 0.1 km/s in ξ.
Note (2): The full list of the seven sample selection criteria is described
in Section 2 of the paper. The selection flag is defined as follows:
v1 = stars selected using criteria (1)-(5) on the pure infrared 2MASS
and WISE data set.
v2 = stars selected using all seven criteria on our full APASS, 2MASS,
and WISE data set.
Note (3): Additional notes defined as follows:
1 = Visual inspection revealed the target to be unambiguously metal-rich.
2 = Ca II H & K in emission.
3 = Broad spectral features.
4 = Evidence of binarity.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 19 A19 --- 2MASS 2MASS identifier (JHHMMSS.ss+DDMMSS.s) (G1)
21- 22 I2 h RAh Hour of Right Ascension (J2000)
24- 25 I2 min RAm Minute of Right Ascension (J2000)
27- 30 F4.1 s RAs Second of Right Ascension (J2000)
32 A1 --- DE- Sign of the Declination (J2000)
33- 34 I2 deg DEd Degree of Declination (J2000)
36- 37 I2 arcmin DEm Arcminute of Declination (J2000)
39- 40 I2 arcsec DEs Arcsecond of Declination (J2000)
42- 46 F5.2 mag Vmag [10.29/14.91]? The V band magnitude
48- 51 F4.2 mag B-V [0.6/1.57]? The (B-V) color index
53- 57 F5.2 mag Jmag [9.04/12.99] 2MASS J band magnitude
59- 63 F5.2 mag Hmag [8.47/12.59] 2MASS H band magnitude
65- 69 F5.2 mag Ksmag [8.39/12.45] 2MASS KS band magnitude
71- 75 F5.2 mag 3.4mag [8.33/12.43] WISE/W1 3.4micron band magnitude
77- 81 F5.2 mag 4.6mag [8.35/12.44] WISE/W2 4.6micron band magnitude
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Global Notes:
Note (G1): 2MASS objects are <2MASS JHHMMSSss+DDMMSSs> in SIMBAD (no decimal
points in the format).
History:
From electronic version of the journal
(End) Prepared by [AAS], Marianne Brouty [CDS] 24-Nov-2016