J/other/ApSS/363.127 Bulge RR Lyrae VVVDR4 photometry (Majaess+, 2018)
Establishing the Galactic Centre Distance Using VVV Bulge RR Lyrae Variables.
Majaess D., Dekany I., Hajdu G., Minniti D., Turner D., Gieren W.
<Astrophys. Space Sci. 363, 127 (2018)>
=2018Ap&SS.363..127M 2018Ap&SS.363..127M (SIMBAD/NED BibCode)
ADC_Keywords: Galactic center ; Stars, variable ; Photometry, infrared
Keywords: Galaxy: center - stars: variables: RR Lyrae
Abstract:
This study's objective was to exploit infrared VVV (VISTA Variables in
the Via Lactea) photometry for high latitude RRab stars to establish
an accurate Galactic Centre distance. RRab candidates were discovered
and reaffirmed (n=4194) by matching Ks photometry with templates via
chisq minimization, and contaminants were reduced by ensuring targets
adhered to a strict period-amplitude (Ks) trend and passed the
Elorietta et al. (2016A&A...595A..82E 2016A&A...595A..82E) classifier. The distance to the
Galactic Centre was determined from a high latitude Bulge subsample
(|b|>4, RGC=8.30±0.36kpc, random uncertainty is relatively
negligible), and importantly, the comparatively low color-excess and
uncrowded location mitigated uncertainties tied to the extinction law,
the magnitude-limited nature of the analysis, and photometric
contamination. Circumventing those problems resulted in a key
uncertainty being the MKs relation, which was derived using LMC RRab
stars (MKs=-(2.66±0.06)logP-(1.03±0.06), (J-Ks)0=(0.31±0.04)logP
+(0.35±0.02), assuming mu0LMC=18.43). The Galactic Centre distance
was not corrected for the cone-effect. Lastly, a new distance
indicator emerged as brighter overdensities in the
period-magnitude-amplitude diagrams analyzed, which arise from blended
RRab and red clump stars. Blending may thrust faint extragalactic
variables into the range of detectability.
Description:
Preliminary VVVDR4 aperture (source table) photometry for the RRab
stars from the VISTA Data Flow System (VDFS) pipeline
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
final-v2.dat 85 4194 Preliminary VVVDR4 aperture (source table)
photometry for the RRab stars from the VISTA
Data Flow System (VDFS) pipeline
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See also:
II/337 : VISTA Variables in the Via Lactea Survey DR1 (Saito+, 2012)
II/348 : VISTA Variable in the Via Lactea Survey DR2 (Minniti+, 2017)
Byte-by-byte Description of file: final-v2.dat
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Bytes Format Units Label Explanations
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1- 11 F11.7 deg RAdeg Right Ascension (J2000)
13- 23 F11.7 deg DEdeg Declination (J2000)
25- 33 F9.7 d Per Period
35- 40 F6.3 mag Jmag VISTA Jmag from the VVVDR4 source table
42- 46 F5.3 mag e_Jmag Uncertainty tied to the VVVDR4 Jmag
48- 53 F6.3 mag Hmag VISTA Hmag from the VVVDR4 source table
55- 59 F5.3 mag e_Hmag Uncertainty tied to the VVVDR4 Hmag
61- 66 F6.3 mag Ksmag VISTA Ksmag from the VVVDR4 source table
68- 72 F5.3 mag e_Ksmag Uncertainty tied to the VVVDR4 Ksmag
74- 85 I12 --- sourceID VVVDR4 source ID
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Acknowledgements:
Daniel Majaess, daniel.majaess(at)gmail.com
(End) Patricia Vannier [CDS] 25-Dec-2018