J/AJ/115/635 Cepheid radial velocities (Metzger+ 1998)
The shape and scale of Galactic rotation from Cepheid kinematics
Metzger M.R., Caldwell J.A.R., Schechter P.L.
<Astron. J. 115, 635 (1998)>
=1998AJ....115..635M 1998AJ....115..635M (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Radial velocities
Keywords: Cepheids - Galaxy: fundamental parameters -
Galaxy: kinematics and dynamics - Galaxy: structure
Abstract:
A catalog of Cepheid variables is used to probe the kinematics of the
Galactic disk. Radial velocities are measured for eight distant
Cepheids toward l=300°; these new Cepheids provide a particularly
good constraint on the distance to the Galactic center, R0. We model
the disk with both an axisymmetric rotation curve and one with a weak
elliptical component, and find evidence for an ellipticity of
0.043±0.016 near the Sun. Using these models, we derive
R0=7.66±0.32kpc and vcirc=237±12km/s. The distance to the
Galactic center agrees well with recent determinations from the
distribution of RR Lyrae variables and disfavors most models with
large ellipticities at the solar orbit.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 32 45 Cepheid radial velocities, 1991 February
table5.dat 47 288 Cepheid data
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See also:
J/A+AS/108/9 : Cepheids fundamental parameters I. (Bersier+, 1994)
J/A+AS/108/25 : Cepeheids fundamental parameters II. (Bersier+, 1994)
J/A+A/318/416 : Classical Cepheids radial velocities + photometry (Pont+ 1997)
J/A+A/323/775 : Cepheids radial velocities and coordinates (Mishurov+ 1997)
Table 1: Radial velocity standards, 1991 February
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Star RV epsf epsV n
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HD 24331 26.6 1.7 1.3 3
HD 39194 16.4 1.7 0.8 4
HD 48381 40.1 1.5 0.5 4
HD 83443 27.4 1.2 0.7 6
HD 83516 43.3 1.2 1.5 7
HD 101266 21.5 1.3 1.5 6
HD 111417 -18.9 1.2 0.8 7
HD 176047 -41.5 1.3 0.6 5
CPD -43 2527 19.3 1.3 1.2 5
HD 74000 205.5 4.6 1.6 4
HD 140283 -171.2 3.2 3.6 3
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Notes: epsf is the formal error in the velocity from the Fourier quotient
epsV=σv/n1/2 is the standard error of the mean of the
individual measurements
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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 --- [CKS91] Caldwell et al. (1991AJ....101.1763C 1991AJ....101.1763C)
Cepheid designation
12- 22 F11.3 d JD Julian date
24- 28 F5.1 km/s RV Radial velocity
30- 32 F3.1 km/s e_RV rms uncertainty on RV
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Table 3: Gamma velocities of new Cepheids
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Cepheid γ efit eMc xi2 Period (d)
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11447-6153 29.1 2.0 1.9 1.5 6.4282
11465-6209 0.9: 4.0 3.8 4.4 11.0984
11492-6257 6.7 1.6 2.5 0.5 3.6798
11521-6200 20.4 1.7 1.7 1.2 6.6039
12003-6213 2.3 1.8 2.2 1.1 9.1266
13190-6235 -31.7 2.2 3.2 1.9 10.1576
13240-6245 -29.9: 3.3 8.6 0.6 15.0598
13323-6224 -48.3 3.0 2.1 2.2 4.2424
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Notes: efit : formal error of the fit
eMC : Additional error estimate, based on
a Monte Carlo simulation
xi2 : Reduced χ2
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Table 4: Calculated parameter for new Cepheids
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Capheid Amp(V) e<K> JDV,max JDK,max Period (d)
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11447-6153 0.65 10.092 0.013 2447962.97 2448337.43 6.4282
11465-6209 0.88 8.558 0.014 2447968.7 2448337.84 11.0984
11492-6257 0.62 10.649 0.009 2447959.80 2448336.00 3.6529
11521-6200 0.63 9.645 0.014 2447958.40 2448335.16 6.5763
12003-6213 0.72 9.125 0.012 2447958.67 2448339.86 9.0131
13190-6235 0.82 8.739 0.015 2447958.76 2448342.12 10.3001
13240-6245 1.21 7.618 0.022 2447966.94 2448337.60 15.2158
13323-6224 0.46 7.910 0.012 2447961.75 2448336.63 4.2424
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Notes: Amp(V) : amplitude (peak-to-peak) of the V-band light curves
JD : epochs of maximum light in both V and K
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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- 9 A9 --- Name Cepheid name
11- 15 F5.1 deg GLON Galactic longitude
17- 21 F5.1 deg GLAT Galactic latitude
23- 27 F5.1 km/s RV Radial velocity
29- 34 F6.4 [d] logP log of the period
36- 41 F6.3 mag <Vmag> Average V magnitude (1)
43- 47 F5.3 mag E(B-V) Reddening
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Note (1): Caldwell & Coulson, 1987AJ.....93.1090C 1987AJ.....93.1090C, and references therein
Pont et al., 1994A&A...285..415P 1994A&A...285..415P
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History: From AJ electronic version
(End) Patricia Bauer [CDS] 17-Mar-1998