J/MNRAS/320/451 A-G star metallicity (Beers+, 2001)
Metallicity estimates for A-, F-, and G-type stars from the
Edinburgh-Cape Blue Object Survey.
Beers T.C., Rossi S., O'Donoghue D., Kilkenny D., Stobie R.S., Koen C.,
Wilhelm R.
<Mon. Not. R. Astron. Soc. 320, 451 (2001)>
=2001MNRAS.320..451B 2001MNRAS.320..451B
ADC_Keywords: Stars, population II ; Abundances, [Fe/H]
Keywords: surveys - stars: Population II - Galaxy: abundances - Galaxy: halo
Abstract:
The Edinburgh-Cape Blue Object Survey is an ongoing project
to identify and analyse a large sample of hot stars selected
initially on the basis of photographic colours (down to a
magnitude limit (B∼18.0) over the entire high-Galactic-latitude
southern sky, and then studied with broad-band UBV photometry and
medium-resolution spectroscopy. Due to unavoidable errors in the
initial candidate selection, stars that are likely metal-deficient
dwarfs and giants of the halo and thick-disc populations are
inadvertently included, yet are of interest in their own right. In
this paper we discuss a total of 206 candidate metal-deficient dwarfs,
subgiants, giants, and horizontal-branch stars with photoelectric
colours redder than (B-V)0=0.3, and with available spectroscopy.
Radial velocities, accurate to ∼10-15km/s, are presented for all of
these stars. Spectroscopic metallicity estimates for these stars are
obtained using a recently recalibrated relation between Ca II K-line
strength and (B-V)0 colour. The identification of metal-poor stars
from this colour-selection technique is remarkably efficient, and
competitive with previous survey methods. An additional sample of 186
EC stars with photoelectric colours in the range -0.4≤(B-V)0<0.3,
photoelectric colours in the range composed primarily of field
horizontal-branch stars and other, higher gravity, A- and B-type
stars, is also analysed. Estimates of the physical parameters Teff,
log g and [Fe/H] are obtained for cooler members of this subsample,
and a number of candidate RR Lyrae variables are identified.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 108 60 Observed quantities for EC programme stars
table2.dat 67 53 Previous identifications for EC programme stars
table4.dat 12 73 Probable horizontal-branch blue (HBB) stars
table5.dat 80 141 Physical parameter estimates - EC hot stars
table6.dat 55 206 Derived quantities - EC cool stars
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See also:
J/AJ/117/981 : Estimation of stellar metal abundance. II. (Beers+, 1999)
J/MNRAS/287/867 : Edinburgh-Cape Blue Object Survey. Zone 1. (Kilkenny+ 1997)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- EC Edinburgh-Cape source name, based on position
11 A1 --- n_EC [a-e] Star peculiarity (1)
13- 14 I2 h RAh Right ascension (B1950.0)
16- 17 I2 min RAm Right ascension (B1950.0)
19- 22 F4.1 s RAs Right ascension (B1950.0)
24 A1 --- DE- Declination sign (B1950.0)
25- 26 I2 deg DEd Declination (B1950.0)
28- 29 I2 arcmin DEm Declination (B1950.0)
31- 32 I2 arcsec DEs Declination (B1950.0)
34- 38 F5.1 deg GLON Galactic longitude
40- 44 F5.1 deg GLAT Galactic latitude
46- 50 F5.2 mag Vmag V magnitude
52- 56 F5.2 mag B-V B-V colour index
58- 62 F5.2 mag U-B U-B colour index
64- 67 F4.2 mag E(B-V) Reddening
69- 72 I4 km/s HRV Heliocentric radial velocity
74- 78 F5.2 0.1nm KP ? Ca II K line index (G2)
80- 83 F4.2 0.1nm HeI1 ? HeI (4026Å) line index (G2)
85- 88 F4.2 0.1nm HeI2 ? HeI (4471Å) line index (G2)
90- 93 F4.2 0.1nm HP2 Balmer line index (Beers et al., 1999,
Cat. J/AJ/117/981)
95- 98 F4.2 0.1nm GP ? G-band index (G2)
100-108 A9 --- SpType Spectral type (2)
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Note (1): Type of stars as follows:
a = Binary ?
b = Variable ?
c = Eclipsing Binary ?
d = Peculiar ?
e = Composite ?
Note (2): A colon (:) indicates stars having possible peculiarities in
their spectra and/or colours, leading to somewhat less confidence in
the proper assignment of their spectral classifications and in the
derived estimates of their physical parameters.
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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- 10 A10 --- EC Edinburgh-Cape star name
12- 13 A2 --- --- [HD]
15- 20 I6 --- HD ? HD (Cat. III/135) number
23- 33 A11 --- DM Durchmusterung (BD, CD, CPD) designation
36- 48 A13 --- BPS CS or BS name
50- 69 A20 --- ONames Other names
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- EC Edinburgh-Cape star name
11 A1 --- n_EC [:] : for stars that may be composite stars
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- EC Edinburgh-Cape star name
12- 15 I4 K Teff Effective temperature
16 A1 --- u_Teff Uncertainty on Teff
18- 20 F3.1 [cm/s2] logg Surface gravity
21 A1 --- u_logg Uncertainty flag on logg
23- 26 F4.1 Sun [Fe/H]WK Metallicity based on Ca II K equivalent width
28- 31 F4.1 Sun [Fe/H]CTA ? Metallicity based on Ca II K line profile
33- 36 F4.1 Sun [Fe/H]MTA ? Metallicity based on Ca II K line profile
for Am stars
37 A1 --- u_[Fe/H]MTA Uncertainty flag on [Fe/H]MTA
39- 42 F4.1 Sun [Fe/H] ? Average metallicity
43 A1 --- u_[Fe/H] Uncertainty flag on [Fe/H]
45- 47 F3.1 --- e_[Fe/H] ? rms uncertainty on [Fe/H]
49- 53 A5 --- Class EC classification (G1)
55- 58 F4.2 mag VMAG ? Absolute V magnitude
60- 64 I5 pc Dist ? Distance
66- 68 A3 --- Notes [rR, ] Notes (1)
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Note (1): Notes as follows:
r = stars exhibit discrepancies between their Balmer-line strengths and
their observed broad-band colours, which might arise from spectroscopic
and photometric observations of an RR Lyrae variable taken `out of
phase'. These identifications are tentative, and should be confirmed
on the basis of further photometric follow-up.
R = RR Lyrae variables
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Byte-by-byte Description of file: table6.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- EC Edinburgh-Cape star name
12- 17 A6 --- Class EC classification (G1)
18 A1 --- u_Class Uncertainty flag on Class
19- 23 F5.2 mag VMAG Absolute V magnitude
25- 28 F4.2 mag VMAG2 ? Secons absolute V magnitude estimate (1)
31- 35 I5 pc Dist Distance
37- 41 I5 pc Dist2 ? Second distance estimate (1)
44- 48 F5.2 Sun [Fe/H]K3 Estimate metallicity by application of Beers
et al., (1999, Cat. J/AJ/117/981) calibration
49 A1 --- u_[Fe/H]K3 Uncertainty flag on [Fe/H]K3
51- 54 F4.2 --- e_[Fe/H]K3 rms uncertainty on [Fe/H]K3
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Note (1): In cases where the type classification is ambiguous, e.g., TO/FHB
or FHB/TO, alternative absolute magnitudes and distances are provided
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Global notes:
Note (G1): EC classification is defined as follows:
FHB = a likely field horizontal-branch star
A = a star with main-sequence gravity typical of A-type stars,
blue metal-poor star (BMPS), and other slightly cooler,
early F-type stars
FHB/A = an indeterminate classification
Am = a star with apparently main-sequence gravity and a large
discrepancy between the metallic-line-region abundance estimate
and those estimates based on the Ca II K line, a phenomenon
often associated with Am (and Ap) stars.
G = giant
SG = subgiant
TO = main-sequence turnoff
Note (G2): Table 3: Line index wavelength bands (Å)
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Line Line Band Blue Sideband Red Sideband
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Ca II-K6 3930.7-3936.7 3903.0-3923.0 4000.0-4020.0
Ca II-K12 3927.7-3939.7 3903.0-3923.0 4000.0-4020.0
Ca II-K18 3924.7-3942.7 3903.0-3923.0 4000.0-4020.0
He I-4026 4020.2-4032.2 4000.0-4020.0 4144.0-4164.0
Hδ-HD12 4095.8-4107.8 4000.0-4020.0 4144.0-4164.0
Hδ-HD24 4089.8-4113.8 4000.0-4020.0 4144.0-4164.0
G-band 4297.5-4312.5 4247.0-4267.0 4362.0-4372.0
He I-4471 4465.7-4477.7 4415.0-4435.0 4490.0-4510.0
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History:
* 23-Mar-2001: From electronic version of the journal
* 22-Mar-2006: several mis-identifications in table2 corrected at CDS:
"SV" acronym changed into "NSV" (concerns 4 stars)
"LP 1723" changed into "LB 1723"
"HD 40021" changed into "HD 40031"
(End) James Marcout, Patricia Bauer [CDS] 23-Mar-2001