J/A+A/605/A100 VVV survey Galactic Bulge Pop. II Cepheids (Bhardwaj+, 2017)
Galactic Bulge Population II Cepheids in the VVV Survey:
period-luminosity relations and a distance to the Galactic center.
Bhardwaj A., Rejkuba M., Minniti D., Surot F., Valenti E., Zoccali M.,
Gonzalez O.A., Romaniello M., Kanbur S.M., Singh H.P.
<Astron. Astrophys. 605, A100 (2017)>
=2017A&A...605A.100B 2017A&A...605A.100B (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable
Keywords: stars: variables: Cepheids - Galaxy: bulge - Galaxy: structure -
galaxies: Magellanic Clouds - distance scale
Abstract:
We present the near-infrared observations of population II Cepheids in
the Galactic bulge from VVV survey. We identify 340 population II
Cepheids in the Galactic bulge from VVV survey based on their match
with OGLE-III Catalogue. The single-epoch JH and multi-epoch Ks
observations complement the accurate periods and optical (VI)
mean-magnitudes from OGLE. The sample consisting of BL Herculis and W
Virginis subtypes is used to derive period-luminosity relations after
correcting mean-magnitudes for the extinction. The absolute magnitudes
for population II Cepheids and RR Lyraes calibrated using Gaia and
Hubble Space Telescope parallaxes, together with calibrated magnitudes
for Large Magellanic Cloud population II Cepheids, are used to obtain
a distance to the Galactic center. The number density for population
II Cepheids is more limited as compared to abundant RR Lyraes but they
are bright and exhibit a wide range in period that provides a robust
period-luminosity relation for an accurate estimate of the distance to
the Galactic center.
Description:
We present a combined OGLE-III and VVV catalogue with periods,
classification, mean magnitudes and extinction for 264 Galactic bulge
population II Cepheids having good-quality Ks-band light curves.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 129 264 Properties of Type II Cepheids in the Galactic bulge
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See also:
J/AcA/61/285 : VI light curves of Galactic Bulge Cepheids (Soszynski+, 2011)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 12 A12 --- VVV-ID VVV Source Identification
16- 24 A9 --- --- [OGLE-BLG-]
25- 33 A9 --- OGLE-ID OGLE Identification (T2CEP-NNN,
OGLE BLG-T2CEP-NNN in Simbad) (1)
37- 42 F6.3 d Period Period of Type II Cepheid
46- 48 A3 --- Class Subtype of Type II Cepheid
52- 57 F6.3 mag <Vmag> ?=99.999 V-band mean magnitude
61- 66 F6.3 mag <Imag> I-band mean magnitude
70- 75 F6.3 mag <Jmag> ?=99.999 J-band mean magnitude
79- 84 F6.3 mag <Hmag> ?=99.999 H-band mean magnitude
88- 93 F6.3 mag <Ksmag> ?=99.999 Ks-band mean magnitude
98-102 F5.3 mag e_<Jmag> ?=9.999 Error in J-band mean magnitude
107-111 F5.3 mag e_<Hmag> ?=9.999 Error in H-band mean magnitude
116-120 F5.3 mag e_<Ksmag> ?=9.999 Error in Ks-band mean magnitude
125-129 F5.3 mag E(J-Ks) Color excess E(J-Ks) (2)
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Note (1): The OGLE identification, Period, subtype and optical mean magnitudes
of Type II Cepheids are taken from OGLE-III (Soszynski et al., 2011,
Cat. J/AcA/61/285).
Note (2): E(J-Ks) values are taken from extinction maps of Gonzalez et al.
(2011A&A...534A...3G 2011A&A...534A...3G).
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Acknowledgements:
Anupam Bhardwaj, anupam.bhardwajj(at)gmail.com
(End) Anupam Bhardwaj [Univ. Delhi, India], Patricia Vannier [CDS] 27-Jul-2017