J/ApJ/835/81 Bright metal-poor stars from HES Survey. II. (Beers+, 2017)
Bright metal-poor stars from the Hamburg/ESO Survey.
II. A chemodynamical analysis.
Beers T.C., Placco V.M., Carollo D., Rossi S., Lee Y.S., Frebel A.,
Norris J.E., Dietz S., Masseron T.
<Astrophys. J., 835, 81-81 (2017)>
=2017ApJ...835...81B 2017ApJ...835...81B (SIMBAD/NED BibCode)
ADC_Keywords: Abundances ; Radial velocities ; Spectroscopy ; Surveys ;
Proper motions ; Photometry, infrared ; Stars, nearby
Keywords: Galaxy: kinematics and dynamics; Galaxy: stellar content;
stars: abundances; stars: carbon; stars: Population II;
stars: kinematics and dynamics
Abstract:
We obtain estimates of stellar atmospheric parameters for a previously
published sample of 1777 relatively bright (9<B<14) metal-poor
candidates from the Hamburg/ESO Survey. The original Frebel+ (2006,
J/ApJ/652/1585; Paper I) analysis of these stars was able to derive
estimates of [Fe/H] and [C/Fe] only for a subset of the sample, due to
limitations in the methodology then available. A new spectroscopic
analysis pipeline has been used to obtain estimates of Teff, logg,
[Fe/H], and [C/Fe] for almost the entire data set. This sample is very
local-about 90% of the stars are located within 0.5kpc of the Sun. We
consider the chemodynamical properties of these stars in concert with
a similarly local sample of stars from a recent analysis of the
Bidelman and MacConnell "weak metal" candidates by Beers+ (2014,
J/ApJ/794/58). We use this combined sample to identify possible
members of the halo stream of stars suggested by Helmi+
(1999Natur.402...53H 1999Natur.402...53H) and Chiba & Beers (2000AJ....119.2843C 2000AJ....119.2843C), as well
as stars that may be associated with stripped debris from the putative
parent dwarf of the globular cluster Omega Centauri, suggested to
exist by previous authors. We identify a clear increase in the
cumulative frequency of carbon-enhanced metal-poor (CEMP) stars with
declining metallicity, as well as an increase in the fraction of CEMP
stars with distance from the Galactic plane, consistent with previous
results. We also identify a relatively large number of CEMP stars with
kinematics consistent with the metal-weak thick-disk population, with
possible implications for its origin.
Description:
In the present paper, we re-analyze medium-resolution (R∼2000)
spectroscopy of the sample of stars from Paper I (Frebel+, 2006,
J/ApJ/652/1585). Medium-resolution follow-up observations were taken
with several telescopes (Siding Spring Observatory (SSO) 2.3m, Kitt
Peak National Observatory (KPNO) 4m, Cerro Tololo Inter-American
Observatory (CTIO) 1.5m, ESO 3.6m, CTIO 4m, AAT 3.9m) in the periods
2003 March-April, 2003 August-2004 April, and 2004 September-October.
Broadband V magnitudes and B-V colors for the majority of our program
objects were obtained from the APASS database (Henden+, 2016, II/336),
supplemented by photometry from a number of sources as described in
Paper I. In a number of cases, we have also used photometry from the
SIMBAD database.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 112 1777 Photometric information and adopted reddening
table2.dat 142 1777 Radial velocities, line indices, atmospheric
parameters, and type assignments
table3.dat 61 1777 Carbon abundance ratios and absolute carbon
abundance estimates
table5.dat 56 1777 Distance estimates and proper motions
table6.dat 91 1777 Space motions and orbital parameters
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See also:
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
I/311 : Hipparcos, the New Reduction (van Leeuwen, 2007)
I/320 : SPM 4.0 Catalog (Girard+, 2011)
I/322 : UCAC4 Catalogue (Zacharias+, 2012)
III/272 : RAVE 4th data release (Kordopatis+, 2013)
J/AJ/90/2089 : Stars of very low metal abundance. I (Beers+, 1985)
J/AJ/103/1987 : Stars of very low metal abundance (Beers+ 1992)
J/AJ/117/981 : Estimation of stellar metal abundance. II. (Beers+, 1999)
J/A+A/358/77 : Hamburg/ESO survey for bright QSOs. III. (Wisotzki+, 2000)
J/AJ/119/2866 : Proper motions of metal-poor stars (Beers+, 2000)
J/ApJ/652/1585 : Bright metal-poor stars from HES survey (Frebel+, 2006)
J/ApJS/168/128 : UBVRcIc photometry of FHB and metal-poor stars (Beers+, 2007)
J/AN/331/474 : Abundances of metal-poor stars (Frebel, 2010)
J/AJ/139/1051 : Carbon-enhanced metal-poor stars in the Galaxy (Placco+, 2010)
J/AJ/141/90 : SEGUE stellar parameter pipeline. V. (Lee+, 2011)
J/MNRAS/412/843 : SAGA extremely metal-poor stars (Suda+, 2011)
J/ApJ/788/180 : Very metal-poor stars in the Milky Way's halo (Carollo+, 2014)
J/ApJ/794/58 : Metal-poor stars in the thick disk of the Galaxy (Beers+, 2014)
J/ApJ/797/21 : Carbon-enhanced metal-poor stars (Placco+, 2014)
J/ApJ/814/121 : CASH project. III. The CEMP star HE0414-0343 (Hollek+, 2015)
J/ApJ/833/20 : Carbon-enhanced metal-poor (CEMP) star abundances (Yoon+, 2016)
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- --- [HE]
4- 12 A9 --- HE Star identifier (HHMM+DDMM; J2000)
13 A1 --- m_HE [ABF] Multiplicity index on HE name
15- 36 A22 --- OName Other star identifier(s)
38- 63 A26 --- HK HK Survey star identifier(s)
65- 69 F5.1 deg GLON Galactic longitude
71- 75 F5.1 deg GLAT Galactic latitude
77- 81 F5.2 mag Vmag [6.3/14.4]? Adopted V band magnitude
83- 87 F5.2 mag B-V [-0.3/1.6]? Adopted (B-V) color index
89- 94 F6.3 mag Jmag [6.9/14.6]? 2MASS J band magnitude (1)
96-101 F6.3 mag J-Ks [-0.3/1.1]? 2MASS (J-Ks) color index (1)
103-107 F5.3 mag E(B-V)S [0.004/0.8] Schlegel+ 1998ApJ...500..525S 1998ApJ...500..525S
E(B-V) estimate
109-112 F4.2 mag E(B-V)A [0/0.5] Corrected E(B-V) estimate (2)
--------------------------------------------------------------------------------
Note (1): Only including stars without flags indicating potential problems
in the listed values.
Note (2): We have applied corrections to E(B-V)S estimates for stars with
reddening greater than E(B-V)S=0.10, as described by
Beers+ (2000, J/AJ/119/2866).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- --- [HE]
4- 12 A9 --- HE Star identifier (HHMM+DDMM; J2000)
13 A1 --- m_HE [ABF] Multiplicity index on HE name
15- 23 A9 --- Note Note on HE (3)
25- 30 F6.1 km/s RVelM [-369/444]? Radial velocity from our
medium-resolution data; ±10km/s
32- 37 F6.1 km/s RVelR [-331/337]? RAVE radial velocity
38- 39 A2 --- f_RVelR Flag on RVelR (4)
41- 46 F6.1 km/s RVelH [-374/442]? Radial velocity (5)
48- 52 F5.2 0.1nm KP [0.07/11.8]? The KP line index (6)
54- 58 F5.2 0.1nm HP2 [0.03/11.4]? Balmer line index (6)
60- 63 F4.2 0.1nm GP [0.01/8.1]? The GP line index (6)
65- 68 I4 K TeffS [4193/8338]? Estimated effective temperature
from non-SEGUE Stellar Parameter Pipeline
(n-SSPP)
70- 73 F4.2 [cm/s2] log(g)S [0.3/5]? Estimated log surface gravity
from n-SSPP
75- 79 F5.2 [Sun] [Fe/H]S [-6.1/0.4]? Estimated metallicity from n-SSPP
81- 84 I4 K TeffR [3200/8000]? Estimated effective temperature
from RAVE
85- 86 A2 --- f_TeffR Flag on TeffR (4)
88- 91 F4.2 [cm/s2] log(g)R [0.09/5.5]? Estimated log surface gravity
from RAVE
92- 93 A2 --- f_log(g)R Flag on log(g)R (4)
95- 99 F5.2 [Sun] [Fe/H]R [-6.7/0.4]? Estimated metallicity from RAVE
100-101 A2 --- f_[Fe/H]R Flag on [Fe/H]R (4)
103-106 I4 K TeffH [4360/6875]? Estimated effective temperature
(5)
107 A1 --- f_TeffH Flag on TeffH (4)
109-112 F4.2 [cm/s2] log(g)H [0.2/5]? Estimated log surface gravity (5)
113 A1 --- f_log(g)H Flag on log(g)H (4)
115-119 F5.2 [Sun] [Fe/H]H [-5.6/0.3]? Estimated metallicity (5)
120 A1 --- f_[Fe/H]H Flag on [Fe/H]H (4)
122-125 I4 K TeffC [3868/8742]? Estimated effective temperature
from corrected n-SSPP
127-132 F6.2 [cm/s2] log(g)C [-0.09/5.7]? Estimated log surface gravity
from corrected n-SSPP
134-138 F5.2 [Sun] [Fe/H]C [-7.1/0.3]? Estimated metallicity
from corrected n-SSPP
140-142 A3 --- Type Adopted type classification (7)
--------------------------------------------------------------------------------
Note (3): Notes on the nature of a small number of stars that deviate from the
majority (e.g., hot stars, sdB and WD stars, known variable stars,
stars with emission lines, extremely late-type stars, etc.), which
preclude their use in later analysis.
Note (4): Flag as follows:
: = quantity should be regarded with some suspicion;
:: = quantity is considered possibly flawed.
Note (5): Either in the published literature or based on more recent
unpublished observations we are aware of.
Note (6): We estimate that errors in the line indices on the order
of 0.1Å are achieved. Units are Angstroms.
Note (7): Assignments to the evolutionary stage, based on the derived
(corrected) stellar atmospheric parameters, are as follows:
D = dwarf, loggC≥4.0 (1243 occurrences);
TO = turnoff, 3.5≤loggC<4.0 (249 occurrences);
G = subgiant or giant, loggC<3.5 (231 occurrences);
FHB = field horizontal-branch stars, TeffC≥6000 and loggC≤3.5
(15 occurrences).
See section 3.4.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- --- [HE]
4- 12 A9 --- HE Star identifier (HHMM+DDMM; J2000)
13 A1 --- m_HE [ABF] Multiplicity index on HE name
15- 19 F5.2 [Sun] [Fe/H]S [-6.1/0.4]? Metallicity; log Fe/H
number abundance (8)
21- 25 F5.2 [Sun] [C/Fe]S [-0.9/3.3]? Carbonicity; log C/Fe
number abundance (8)
27- 28 A2 --- Det Detection flag (9)
30- 35 F6.3 --- CC ? Correlation coefficient (10)
37- 41 F5.2 0.1nm EW [0.1/15]? Equivalent width of CH G-band;
in units of Angstroms
43- 47 F5.2 [Sun] [Fe/H]C [-7.1/0.3]? Corrected metallicity (11)
49- 53 F5.2 [Sun] [C/Fe]C [-1.3/3.2]? Corrected Carbonicity (12)
55- 59 F5.2 [-] A(C) [3.8/61]? Absolute carbon abundance;
logε(C)
61 A1 --- CEMP Carbon-enhanced metal-poor flag (13)
--------------------------------------------------------------------------------
Note (8): The n-SSPP estimate.
Note (9): Flag as follows:
D = detected;
L = lower limit;
U = uper limit;
X = non-detection.
Note (10): Obtained between the observed spectrum and the
best-matching [C/Fe] from the model grids.
Note (11): [Fe/H]C=[Fe/H]S-(-0.232.[Fe/H]S-0.428).
See section 3.3 for further explanations.
Note (12): Beers+ (2014, J/ApJ/794/58) also used literature values of [C/Fe],
based on high-resolution spectroscopic analyses, to derive
corrections for the n-SSPP estimates of [C/Fe], as below:
[C/Fe]C=[C/Fe]S-(-0.068.[C/Fe]S+0.273) (Equation (4)).
See section 3.3 for further explanations.
Note (13): Flag as follows:
C = carbon-enhanced metal-poor (CEMP) (48 occurrences);
[C/Fe]C>+0.7, CC≥0.7, and EW≥1.2.
I = intermediate CEMP (29 occurrences);
+0.5<[C/Fe]C≤+0.7, CC≥0.7, and EW≥1.2.
N = carbon normal (1362 occurrences);
[C/Fe]C≤+0.5, CC≥+0.7, and EW≥1.2.
U = upper limit on the carbon ratio (116 occurrences).
X = No carbon measurements (222 occurrences).
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table5.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- --- [HE]
4- 12 A9 --- HE Star identifier (HHMM+DDMM; J2000)
13 A1 --- m_HE [ABF] Multiplicity index on HE name
15- 17 A3 --- Type Assigned type classification (14)
19- 24 F6.3 kpc Dist [0.01/11]? Photometric distance estimate
26- 30 F5.3 kpc e_Dist [0.003/1.6]? Uncertainty in Dist
32- 37 F6.1 mas/yr pmRA [-230/246]? Proper motion along Right Ascension
39- 44 F6.1 mas/yr pmDE [-547/69]? Proper motion along Declination
46- 49 F4.1 mas/yr e_pmRA [0.5/15]? Uncertainty in pmRA
51- 54 F4.1 mas/yr e_pmDE [0.4/19.2]? Uncertainty in pmDE
56- 56 A1 --- Ref Source of the adopted proper motion (15)
--------------------------------------------------------------------------------
Note (14): Type as follows:
D = dwarf (1241 occurrences);
FHB = field horizontal-branch stars (15 occurrences);
TO = turnoff (249 occurrences);
G = subgiant or giant (231 occurrences).
G,D (1 occurrence).
Note (15): Source as follows:
U = UCAC4 (Zacharias+ 2013, I/322);
S = SPM4 (Girard+, 2011, I/320);
H = Hipparcos (van Leeuwen 2007, I/311) or Tycho II (Hog+ 2000, I/259).
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Byte-by-byte Description of file: table6.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- --- [HE]
4- 12 A9 --- HE Star identifier (HHMM+DDMM; J2000)
13 A1 --- m_HE [ABF] Multiplicity index on HE name
15- 20 F6.3 kpc R ? R position in meridional plane
22- 27 F6.3 kpc Z ? Z position in meridional plane
29- 32 I4 km/s U [-455/606]? Velocity from the Galactic center
34- 37 I4 km/s V [-741/1499]? Velocity along Galactic rotation
39- 42 I4 km/s W [-408/399]? Velocity perpendicular to Galactic plane
44- 46 I3 km/s e_U ? Uncertainty in U
48- 50 I3 km/s e_V [0/229]? Uncertainty in V
52- 54 I3 km/s e_W ? Uncertainty in W
56- 59 I4 km/s VR [-390/622]? Velocity projected onto
Galactic plane (16)
61- 64 I4 km/s Vphi [-887/1240]? Derived rotation velocity
66- 70 F5.2 kpc rperi [0.01/13]? Perigalactic radius
72- 77 F6.2 kpc rapo [5.8/177]? Apogalactic radius
79- 84 F6.2 kpc Zmax [0.04/158]? Derived maximum distance
from Galactic plane
86- 89 F4.2 --- ecc ? Derived orbital eccentricity
91 I1 --- In INOUT parameter (1: star is accepted for the
kinematic analysis)
--------------------------------------------------------------------------------
Note (16): Positive in the direction away from the Galactic center.
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History:
From electronic version of the journal
References:
Frebel et al. Paper I. 2006ApJ...652.1585F 2006ApJ...652.1585F Cat. J/ApJ/652/1585
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 11-Aug-2017