J/AJ/117/2329 Spectroscopy of hot stars in the halo. III (Wilhelm+, 1999)
Spectroscopy of hot stars in the galactic halo. III. Analysis of a large
sample of field horizontal-branch and other A-type stars
Wilhelm R., Beers T.C., Sommer-Larsen J., Pier J.R., Layden A.C.,
Flynn C., Rossi S., Christensen P.R.
<Astron. J. 117, 2329 (1999)>
=1999AJ....117.2329W 1999AJ....117.2329W
ADC_Keywords: Abundances, [Fe/H] ; Photometry, UBV ; Stars, horizontal branch
Keywords: Galaxy: halo - stars: horizontal-branch - stars: Population II
Abstract:
We present results from an analysis of medium-resolution spectroscopy
and UBV photometry for a sample of 1121 A-type stars in the halo (and
disk) of the Galaxy. A previously developed calibration technique is
used to assign estimates of effective temperature, surface gravity,
and stellar metal abundance, as parametrized by [Fe/H]. Radial
velocities are reported with an accuracy of ∼10 km.s-1. Distance
estimates are obtained for the stars with well-determined luminosity
classes. Note that although we refer to "A-type" stars, which dominate
the present sample, the present data set includes roughly 100 stars of
later spectral types, as a result of the temperature range we have
chosen to explore in this paper (6000 K ≤ Teff ≤ 10,000 K).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 106 1121 Observed properties of the program sample
table2a.dat 80 140 Physical parameters for the Am/Ap subsample
table2b.dat 83 444 Physical parameters for the FHB subsample
table2c.dat 82 416 Physical parameters for the A V subsample
table2d.dat 83 121 Physical parameters for the FHB/A subsample
table3.dat 30 19 Known variable stars
tablea1.dat 52 58 Additional photometry for hot star candidates
tableb1.dat 45 81 Program stars with duplicate HK survey
identifications
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See also:
J/AJ/87/1515 : UBV photometry of AB stars in halo (Pier, 1982)
J/ApJS/53/791 : Spectroscopy of AB stars in halo (Pier, 1983)
J/AJ/90/2089 : Stars of very low metal abundance. (Beers+, 1985)
J/PASP/102/1392 : UBV photometry from HK survey. (Doinidis+ 1990)
J/PASP/103/973 : Photoelectric UBV from HK survey. (Doidinis+ 1991)
J/ApJS/76/1001 : UBV photometry of HK survey stars (Preston+, 1991)
J/AJ/103/267 : Spectrocopy of hot stars in galactic halo (Beers+ 1992)
J/AJ/103/1987 : Stars of very low metal abundance (Beers+ 1992)
J/AJ/108/268 : HK survey emission-line candidates positions (Beers+ 1994)
J/AJ/108/538 : Metal-poor MS stars UBV photometry (Preston+ 1994)
J/AJ/112/1188 : HK survey emission-line candidates (Beers+ 1996)
J/ApJS/123/639 : UBV photometry of metal-weak candidates (Norris+, 1999)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- BPS Star Name (field-number)
15 A1 --- f_BPS [ab] Flag indicating new photometry (1)
19- 20 I2 h RAh Right Ascension (B1950)
22- 23 I2 min RAm Right Ascension (B1950)
25- 28 F4.1 s RAs Right Ascension (B1950)
30 A1 --- DE- Sign of the Declination (B1950)
31- 32 I2 deg DEd Declination (B1950)
34- 35 I2 arcmin DEm Declination (B1950)
37- 38 I2 arcsec DEs Declination (B1950)
40- 44 F5.2 mag Vmag V band magnitude
46- 50 F5.2 mag B-V The B-V color
55- 59 F5.2 mag U-B ? The U-B color
61- 65 F5.2 mag E(B-V) The B-V reddening
71- 74 F4.1 0.1nm EqWK ? Equivalent width of the CaII K line
76- 79 F4.1 0.1nm Ddelta Line width of Hδ at 20% below the
local continuum level
81- 84 F4.1 0.1nm Dgamma Line width of Hγ at 20% below the
local continuum level
87- 90 I4 km/s Vhelio Heliocentric radial velocity
92 A1 --- u_Vhelio Indicates an uncertain radial velocity
95 A1 --- Obs1 Observatory's code where data was obtained (2)
97 A1 --- Obs2 Second observatory's code where data was
obtained (2)
99 A1 --- Obs3 Third observatory's code where data was
obtained (2)
101-108 A8 --- Class MK Stellar classification
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Note (1):
a = New CTIO photometry
b = New Siding Spring Observatory photometry by Norris, Ryan, & Beers
(1999ApJS..123..639N 1999ApJS..123..639N)
Note (2):
E = European Southern Observatory
H = Beers et al. (1992AJ....103..267B 1992AJ....103..267B)
K = Kitt Peak National Observatory
L = Lowell observatory
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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- 13 A13 --- BPS Star name
16- 20 I5 K Teff Effective temperature
22 A1 --- u_Teff Uncertain Teff flag
26- 28 F3.1 [cm/s2] log(g) The log of the surface gravity
30 A1 --- u_log(g) Uncertain log(g) flag
36- 39 F4.1 [Sun] Wk ? The [Fe/H] abundance from the CaII
K-line equivalent width technique
43- 46 F4.1 [Sun] CTA ? The [Fe/H] abundance from the CaII
K template matching technique
50- 53 F4.1 [Sun] MTA ? The [Fe/H] abundance from the metallic-
line region template matching procedure
55 A1 --- u_MTA Uncertain MTA flag
57- 60 F4.1 [Sun] AVG ? Average [Fe/H] abundance from best estimate
62 A1 --- u_AVG Abundance obtained from Lowell data
65- 67 F3.1 [Sun] Diff ? Absolute difference between the two most
consistent metallicity indicators
71- 74 F4.1 kpc Dist ? Distance estimate
79- 83 A5 --- Text Comment on star (1)
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Note (1): abbreviations are:
r = Noted in present analysis as a candidate variable star
rr = noted by Preston et al. (1991ApJS...76.1001P 1991ApJS...76.1001P) as a candidate
variable star
RR = noted in Table 3 as an RR Lyrae variable
B = classified by Preston et al. (J/AJ/108/538) as a BMP star
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- BPS CS designation
15- 23 A9 --- OtherName Other Name
26- 30 A5 --- Class Class
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- BPS CS designation
15- 16 I2 h RAh Right ascension (1950.0)
18- 19 I2 min RAm Right ascension (1950.0)
21- 24 F4.1 s RAs Right ascension (1950.0)
26 A1 --- DE- Declination sign (1950.0)
27- 28 I2 deg DEd Declination (1950.0)
30- 31 I2 arcmin DEm Declination (1950.0)
33- 34 I2 arcsec DEs Declination (1950.0)
36- 40 F5.2 mag Vmag V magnitude
42- 46 F5.2 mag B-V B-V colour index
48- 52 F5.2 mag U-B U-B colour index
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Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 13 A13 --- BPS Catalogued star name
17- 29 A13 --- BPS1 Alternate name 1
33- 45 A13 --- BPS2 Alternate name 2
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History:
From AJ electronic edition.
References:
(Paper II) Wilhelm+ 1999AJ....117.2308W 1999AJ....117.2308W
(Paper I) Beers+ 1992AJ....103..267B 1992AJ....103..267B
(End) Greg Schwarz [AAS] 25-Apr-2000