J/MNRAS/363/734 Sculptor dSph variables metal abundances (Clementini+, 2005)
The metal abundance distribution of the oldest stellar component in the
Sculptor dwarf spheroidal galaxy.
Clementini G., Ripepi V., Bragaglia A., Fiorenzano A.F.M., Held E.V.,
Gratton R.G.
<Mon. Not. R. Astron. Soc., 363, 734-748 (2005)>
=2005MNRAS.363..734C 2005MNRAS.363..734C
ADC_Keywords: Clusters, globular ; Stars, variable ; Abundances
Keywords: stars: abundances - stars: evolution - stars: Population II -
stars: variables: other - galaxies: individual: Sculptor
Abstract:
Low-resolution spectroscopy obtained with FORS2 at the Very Large
Telescope (VLT) has been used for the measurement of individual metal
abundances ([Fe/H]) for 110 variable stars, including 107 RR Lyrae
stars and one anomalous Cepheid, and to trace the metal distribution
of the oldest stellar component in the Sculptor dwarf spheroidal
galaxy. The RR Lyrae stars are spread over a 15x15arcmin2 area
around the galaxy centre.
Description:
Observations of 110 variable stars (107 RR Lyrae, 1 anomalous Cepheid,
1 binary system and 1 variable of unknown type) in Sculptor and of RR
Lyrae stars in four Galactic globular clusters (namely, M2, M15, NGC
6171 and NGC 6441) were carried out using FORS2 (Focal
Reducer/low-dispersion Spectrograph 2), mounted on the European
Southern Obseratory (ESO) VLT (Paranal, Chile). The data were
collected in service mode during the period 2003 July 29 to August 5.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 52 14 Log of the observations
table2.dat 117 138 Line indices and metal abundances of variable stars
in Sculptor
tableb.dat 90 21 Line indices and metal abundances of RR Lyrae stars
in the globular clusters M15, M4 and NGC 6171
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See also:
J/A+AS/112/407 : Variable Stars in the Sculptor dwarf galaxy (Kaluzny+, 1995)
J/AJ/110/704 : RR Lyrae Variables in M15 (Silbermann+ 1995)
J/AJ/113/1711 : RR Lyrae in NGC 6171 (Clement+ 1997)
J/AJ/117/2868 : NGC 7089 RR Lyrae BV photometry (Lee+, 1999)
J/A+AS/121/95 : Atmospheric parameters for 24 clusters (Carreta+ 1997)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 A9 --- Field Field
12- 13 I2 h RAh Right ascension (J2000)
15- 16 I2 min RAm Right ascension (J2000)
18- 21 F4.1 s RAs Right ascension (J2000)
23 A1 --- DE- Declination sign (J2000)
24- 25 I2 deg DEd Declination (J2000)
27- 28 I2 arcmin DEm Declination (J2000)
30- 33 F4.1 arcsec DEs Declination (J2000)
35- 44 A10 "YYYY/MM/DD" Date Observation date
46- 49 I4 s ExpTime Exposition time
51- 52 I2 --- NVar Number of variable stars observed in
each mask
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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- 4 I4 -- Star Star number, OGLE Scl NNNN in Simbad (1)
6- 12 A7 --- Type Type of the star (2)
14- 21 F8.6 d Per Period (2)
23- 34 F12.4 d Epoch Epoch in HJD
36- 41 F6.3 mag <Vmag> ?=- Mean V magnitude (2)
43- 54 F12.4 d HJD HJD at half exposure
56- 60 F5.3 --- phi Phase
62- 66 F5.3 --- K K metallicity index
68- 72 F5.3 --- Hdelta Hdelta metallicity index
74- 78 F5.3 --- Hgamma Hgamma metallicity index
80- 84 F5.3 --- Hbeta Hbeta metallicity index
86- 90 F5.3 --- Mean H metallicity index
92- 97 F6.3 --- MI Metallicity index
99-103 F5.2 [Sun] [Fe/H]ZW ? Metallicity in the scale of
Zinn & West, 1984ApJS...55...45Z 1984ApJS...55...45Z
105-109 F5.2 [Sun] [Fe/H]CG ? Metallicity in the scale of
Carretta & Gratton, 1997, J/A+AS/121/95
111-113 I3 km/s RV Radial velocity
115-117 A3 --- Notes Notes (3)
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Note (1): Identifiers are from Kaluzny et al. (1995, Cat. J/A+AS/112/407)
Note (2): Along with types, periods and mean magnitudes (in intensity average)
they were redetermined from the study of the light curves based on
data from Kaluzny et al. (1995, Cat. J/A+AS/112/407).
In a number of cases (marked with notes) they differ significantly
from values published in Kaluzny et al. (1995, Cat. J/A+AS/112/407)
Note (3): Notes as follows:
d = Kovacs (2001A&A...375..469K 2001A&A...375..469K) classifies star 59, 1439 and 3016 as
suspected double-mode RR Lyrae stars, with periodicities of
0.359 68/0.4837; 0.35604/0.47809 and 0.36033/0.48401d,
respectively. Our study of the light curves does not confirm
these findings, we think these stars are monoperiodic c-type
variables with noisy light curves.
e = We think this is a double-mode RR Lyrae, we list the first
overtone period
f = Classification and periods differ significantly from Kaluzny
et al. (1995, Cat. J/A+AS/112/407), who published aliases of
the periodicities preferred here. Star 3710 is a suspected
binary system ('Bin').
g = Noisy spectrum
h = We think this RR Lyrae could either be a double-mode or be
affected by the Blazhko effect (Bl, Blazhko 1907AN....175..325B 1907AN....175..325B)
i = G-band visible
j = Kovacs (2001A&A...375..469K 2001A&A...375..469K) classifies these variables as
double-mode RR Lyrae stars, respectively, with periodicities of
0.35427/0.47546 (3044), 0.35699/0.47975 (3104) and
0.35453/0.47630 (3143) d
k = Variable star of unknown type
l = Incomplete light curve
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Byte-by-byte Description of file: tableb.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Field Cluster name
10- 12 A3 -- Star Variable star number (1)
13 A1 --- n_Star [cd] Note on Star (3)
15- 26 F12.4 d Epoch Epoch in HJD
28- 30 A3 --- Type Type of the star
32- 36 F5.3 --- phi Phase (2)
38- 42 F5.3 --- K K metallicity index
44- 48 F5.3 --- Hdelta Hdelta metallicity index
50- 54 F5.3 --- Hgamma Hgamma metallicity index
56- 60 F5.3 --- Hbeta Hbeta metallicity index
62- 66 F5.3 --- Mean H metallicity index
68- 73 F6.3 --- MI Metallicity index
75- 79 F5.2 [Sun] [Fe/H]ZW ? Metallicity in the scale of
Zinn & West, 1984ApJS...55...45Z 1984ApJS...55...45Z
81- 85 F5.2 [Sun] [Fe/H]CG ? Metallicity in the scale of
Carretta & Gratton, 1997A&AS..121...95C 1997A&AS..121...95C
87- 90 I4 km/s RV Radial velocity
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Note (1): Star identifiers are from Sawyer Hogg on line catalogue of variable
stars in Galactic globular clusters published by Clement et al.
(2001AJ....122.2587C 2001AJ....122.2587C)
Note (2):
-- For M15: Phases were calculated from the HJD of observation using
epochs and periods corrected according to the rates of period changes
published by Silbermann & Smith (1995, Cat. J/AJ/110/704)
-- For M4 : Phases of the spectra were derived from the HJD of
observation and the ephemerides published by Lee & Carney
(1999AJ....117.2868L 1999AJ....117.2868L)
-- For NGC 6171: Phases were derived from the HJD of observation, the
periods published by Clement & Shelton (1997, Cat. J/AJ/113/1711)
and the epochs we estimated from the study of the light curves
published from the same authors.
V2 was not observed by Clement & Shelton (1997, Cat. J/AJ/113/1711),
for this star the adopted ephemerides, from Coutts & Sawyer Hogg
(1971, Publ. David Dunlap Obs. 3, 62), may be no longer valid.
Note (3): Notes as follows:
c = Variable stars V26 and V32 correspond to stars LC608 and LC864 of
Lee & Carney (1999AJ....117.2868L 1999AJ....117.2868L), respectively.
d = Doubtful identification
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 03-May-2006