J/AJ/146/141 BV photometry of dwarf Cepheids in Carina (Vivas+, 2013)
A comprehensive, wide-field study of pulsating stars in the Carina dwarf
spheroidal galaxy.
Vivas A.K., Mateo M.
<Astron. J., 146, 141 (2013)>
=2013AJ....146..141V 2013AJ....146..141V
ADC_Keywords: Galaxies, nearby ; Stars, variable ; Photometry, UBV ; Reddening
Keywords: galaxies: dwarf - galaxies: individual: Carina -
galaxies: stellar content - Local Group - stars: variables: general
Abstract:
We report the detection of 388 pulsating variable stars (and some
additional miscellaneous variables) in the Carina dwarf spheroidal
galaxy over an area covering the full visible extent of the galaxy and
extending a few times beyond its photometric (King) tidal radius along
the direction of its major axis. Included in this total are 340 newly
discovered dwarf Cepheids (DCs), which are mostly located ∼2.5mag
below the horizontal branch and have very short periods (<0.1days),
typical of their class and consistent with their location on the upper
part of the extended main sequence of the younger populations of the
galaxy. Several extra-tidal DCs were found in our survey up to a
distance of ∼1° from the center of Carina. Our sample also
includes RR Lyrae stars and anomalous Cepheids, some of which were
found outside the galaxy's tidal radius as well. This supports past
works that suggest that Carina is undergoing tidal disruption. We use
the period-luminosity relationship for DCs to estimate a distance
modulus of µ0=20.17±0.10mag, in very good agreement with the
estimate from RR Lyrae stars. We find some important differences in
the properties of the DCs of Carina and those in Fornax and the LMC,
the only extragalactic samples of DCs currently known. These
differences may reflect a metallicity spread, depth along the line of
sight, and/or different evolutionary paths of the DC stars.
Description:
Multi-epoch observations of eight fields around the Carina dSph galaxy
were taken with the MOSAIC-II camera at the 4m Blanco Telescope at
Cerro Tololo Inter-American Observatory (CTIO), Chile, during an
interval of six consecutive nights in 2007 December. The MOSAIC-II
camera consists of eight 2048*4096 CCDs
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 85 38 Properties of the RR Lyrae stars
table3.dat 78 10 Properties of the anomalous Cepheid stars
table4.dat 92 340 Properties of the dwarf Cepheid stars
table5.dat 84 9 Properties of the miscellaneous periodic variables
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See also:
J/ApJ/649/201 : Velocities and Washington photometry in Carina (Munoz+, 2006)
J/AJ/131/895 : Stars in the Carina dwarf spheroidal galaxy (Koch+, 2006)
J/AJ/130/2677 : Stars in the Carina dSph galaxy field (Majewski+, 2005)
J/AJ/126/197 : The Carina projects. I. Bright variables (Dall'Ora+, 2003)
J/AJ/115/1840 : BV photometry in Carina dwarf galaxy (Hurley-Keller+ 1998)
J/AJ/115/1856 : Dwarf Cepheids in Carina (Mateo+, 1998)
J/AJ/114/1458 : The Carina Dwarf (Mighell 1997)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Name RR Lyrae star identification (RRL-NN)
<[VM2013] RRL-NN> in Simbad
8- 17 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
19- 28 F10.6 deg DEdeg Declination in decimal degrees (J2000)
30- 34 F5.2 mag <Bmag> Mean B-band magnitude
36- 40 F5.2 mag <Vmag> Mean V-band magnitude
42- 45 F4.2 mag Bamp The B-band amplitude
47- 50 F4.2 mag Vamp The V-band amplitude
52- 53 I2 --- o_<Bmag> Number of Bmag observations
55- 56 I2 --- o_<Vmag> Number of Vmag observations
58- 62 F5.3 d Per Period
64- 68 F5.3 mag E(B-V) The (B-V) color excess
70- 71 A2 --- Type1 [ab c] RR Lyrae type (RRab or RRc)
73- 76 A4 --- [SMS86] Name in Dall'Ora et al. 2003 (J/AJ/126/197)
78- 79 A2 --- Type2 [ab cd] RR Lyrae type (RRab, RRc, RRd) from
Dall'Ora et al. 2003 (J/AJ/126/197)
81- 85 F5.3 d Per2 ? Period in Dall'Ora et al. 2003 (J/AJ/126/197)
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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- 5 A5 --- Name Cepheid star identification (AC-NN)
<[VM2013] AC-NN> in Simbad
7- 16 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
18- 27 F10.6 deg DEdeg Declination in decimal degrees (J2000)
29- 33 F5.2 mag <Bmag> Mean B-band magnitude
35- 39 F5.2 mag <Vmag> Mean V-band magnitude
41- 44 F4.2 mag Bamp The B-band amplitude
46- 49 F4.2 mag Vamp The V-band amplitude
51- 52 I2 --- o_<Bmag> Number of Bmag observations
54- 55 I2 --- o_<Vmag> Number of Vmag observations
57- 61 F5.3 d Per Period
63- 67 F5.3 mag E(B-V) The (B-V) color excess
69- 72 A4 --- [SMS86] Name in Dall'Ora et al. 2003 (J/AJ/126/197)
74- 78 F5.3 d Per2 ? Period in Dall'Ora et al. 2003 (J/AJ/126/197)
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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- 6 A6 --- Name Dwarf Cepheid star identification (DC-NNN)
<[VM2013] DC-NNN> in Simbad
8- 17 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
19- 28 F10.6 deg DEdeg Declination in decimal degrees (J2000)
30- 34 F5.2 mag <Bmag> Mean B-band magnitude
36- 40 F5.2 mag <Vmag> Mean V-band magnitude
42- 45 F4.2 mag Bamp The B-band amplitude
47- 50 F4.2 mag Vamp The V-band amplitude
52- 53 I2 --- o_<Bmag> Number of Bmag observations
55- 56 I2 --- o_<Vmag> Number of Vmag observations
58- 64 F7.5 d Per Period
66- 72 F7.5 d Per2 ? Alternative period; possible alias
74- 78 F5.3 mag E(B-V) The (B-V) color excess
80 A1 --- Mode [F] Pulsation Mode (F=Fundamental)
82- 84 A3 --- [MHN98] Name in Mateo et al. 1988 (J/AJ/115/1856)
86- 92 F7.5 d Per3 ? Period in Mateo et al. 1988 (J/AJ/115/1856)
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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- 5 A5 --- Name Periodic variable star identification (Mis-N)
<[VM2013] Mis-N> in Simbad
7- 16 F10.6 deg RAdeg Right Ascension in decimal degrees (J2000)
18- 27 F10.6 deg DEdeg Declination in decimal degrees (J2000)
29- 33 F5.2 mag <Bmag> Mean B-band magnitude
35- 39 F5.2 mag <Vmag> Mean V-band magnitude
41- 44 F4.2 mag Bamp The B-band amplitude
46- 49 F4.2 mag Vamp The V-band amplitude
51- 52 I2 --- o_<Bmag> Number of Bmag observations
54- 55 I2 --- o_<Vmag> Number of Vmag observations
57- 61 F5.3 d Per Period
63- 67 F5.3 mag E(B-V) The (B-V) color excess
69- 84 A16 --- Type Variable type
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Sylvain Guehenneux [CDS] 23-Jul-2014