J/A+A/606/A92 Gaia LMC eclipsing binary and multiple systems (Mowlavi+, 2017)
Gaia eclipsing binary and multiple systems. Two-Gaussian models applied to
OGLE-III eclipsing binary light curves in the Large Magellanic Cloud.
Mowlavi N., Lecoeur-Taibi I., Holl B., Rimoldini L., Barblan F., Prsa A.,
Kochoska A., Suveges M., Eyer L., Nienartowicz K., Jevardat G., Charnas J.,
Guy L., Audard M.
<Astron. Astrophys. 606, A92 (2017)>
=2017A&A...606A..92M 2017A&A...606A..92M (SIMBAD/NED BibCode)
ADC_Keywords: Surveys ; Magellanic Clouds ; Binaries, eclipsing
Keywords: binaries: eclipsing - Magellanic Clouds - methods: data analysis -
catalogs - surveys
Abstract:
The advent of large scale multi-epoch surveys raises the need for
automated light curve (LC) processing. This is particularly true for
eclipsing binaries (EBs), which form one of the most populated types
of variable objects. The Gaia mission, launched at the end of 2013, is
expected to detect of the order of few million EBs over a 5-year
mission.
We present an automated procedure to characterize EBs based on the
geometric morphology of their LCs with two aims: first to study an
ensemble of EBs on a statistical ground without the need to model the
binary system, and second to enable the automated identification of
EBs that display atypical LCs.
We model the folded LC geometry of EBs using up to two Gaussian
functions for the eclipses and a cosine function for any
ellipsoidal-like variability that may be present between the eclipses.
The procedure is applied to the OGLE-III data set of EBs in the Large
Magellanic Cloud (LMC) as a proof of concept. The bayesian information
criterion is used to select the best model among models containing
various combinations of those components, as well as to estimate the
significance of the components.
Based on the two-Gaussian models, EBs with atypical LC geometries are
successfully identified in two diagrams, using the Abbe values of the
original and residual folded LCs, and the reduced chi2. Cleaning the
data set from the atypical cases and further filtering out LCs that
contain non-significant eclipse candidates, the ensemble of EBs can be
studied on a statistical ground using the two-Gaussian model
parameters. For illustration purposes, we present the distribution of
projected eccentricities as a function of orbital period for the
OGLE-III set of EBs in the LMC, as well as the distribution of their
primary versus secondary eclipse widths.
Description:
Attributes of the two-Gaussian models fitted to the folded light
curves of OGLE-III eclipsing binaries of the Large Magellanic Cloud. A
description of the columns is provided in Table A.1 in the Appendix of
the article.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
o3lmcebs.dat 892 26118 Attributes of the two-Gaussian models fitted to
the folded light curves of OGLE-III eclipsing
binaries of the Large Magellanic Cloud
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See also:
I/337 : Gaia DR1 (Gaia Collaboration, 2016)
J/AcA/61/103 : OGLE IIII LMC eclipsing binaries (Graczyk+, 2011)
J/MNRAS/443/432 : Eclipsing binaries in LMC (Muraveva+, 2014)
Byte-by-byte Description of file: o3lmcebs.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- ID OGLE-III eclipsing binary source ID in
the LMC (sourceId)
7- 17 F11.6 d Per Orbital period (period)
19- 24 A6 --- Model Adopted two-Gaussian model (model) (1)
26 I1 --- Nparam Number of parameters in the two-Gaussian
model (numParams)
28- 50 F23.18 d Epoch1 Epoch of primary minimum (HJD-2450000)
(primaryEpoch)
52- 67 F16.13 mag cst Value of the constant in the
two-Gaussian model (cst)
69- 88 F20.18 mag e_cst Uncertainty on cst (cstErr)
90-109 E20.15 --- mu1 ? Phase of primary eclipse minimum (mu1)
111-130 E20.15 --- e_mu1 ? Uncertainty on mu1 (mu1Err)
132-151 E20.15 --- sigma1 ? Gaussian width, in phase, of the primary
eclipse (sigma1)
153-172 E20.15 --- e_sigma1 ? Uncertainty on sigma1 (sigma1Err)
174-191 E18.14 mag d1 ? Gaussian depth of the primary eclipse
(d1)
193-211 E19.15 mag e_d1 ? Uncertainty on d1 (d1Err)
213-232 E20.15 --- mu2 ? Phase of secondary minimum (mu2)
234-253 E20.15 --- e_mu2 ? Uncertainty on mu2 (mu2Err)
255-274 E20.15 --- sigma2 ? Gaussian width, in phase, of the
secondary eclipse (sigma2)
276-295 E20.15 --- e_sigma2 ? Uncertainty on sigma2 (sigma2Err)
297-315 E19.15 mag d2 ? Gaussian depth of the secondary eclipse
(d2)
317-336 E20.15 mag e_d2 ? Uncertainty on d2 (d2Err)
338-357 E20.15 --- PhaseCEC ? Phase of cosine function for the
ellipsoidal component (muForCosHalfP)
359-378 E20.15 mag ACEC ? Amplitude of cosine function for the
ellipsoidal component (aCosHalfP)
380-399 E20.15 mag e_ACEC ? Uncertainty on aCosHalfP (aCosHalfPErr)
401-420 E20.15 --- Width1 ? Primary eclipse duration in phase
(width1)
422-439 E18.14 mag Depth1 ? Primary eclipse depth (depth1)
441-459 E19.15 --- Width2 ? Secondary eclipse duration in phase
(width2)
461-479 E19.15 mag Depth2 ? Secondary eclipse depth (depth2)
481-499 F19.17 --- maxPhaseGap Largest phase gap in folded light curve
(maxPhaseGap)
501-517 F17.15 --- PhaseClum Phase clumpiness (phaseClumpiness)
519-536 E18.14 --- phaseCovE1 ? Phase coverage of primary eclipse
(phaseCoverageEcl1)
538-554 E17.13 --- phaseCovE2 ? Phase coverage of secondary eclipse
(phaseCoverageEcl2)
556-573 E18.14 --- signiE1 ? Significance of primary eclipse
(significance_ecl1)
575-594 E20.15 --- signiE2 ? Significance of secondary eclipse
(significance_ecl2)
596-615 E20.15 --- signiEll ? Significance of ellipsoidal-like
variability (significance_ell)
617-633 E17.13 --- E1dOMMErr ? Gaussian depth over mean measurement
uncertainty for primary eclipse
(ecl1_dOverMeanMagError)
635-651 E17.13 --- E2dOMMErr ? Gaussian depth over mean measurement
uncertainty for secondary eclipse
(ecl2_dOverMeanMagError)
653-671 F19.17 --- abbeFlc Abbe value of the folded light curve
(abbeFlc)
673-690 F18.16 --- abbeFlcRes Abbe value of the residual folded light
curve (abbeFlcResidual)
692-710 F19.15 --- rChi2 Reduced chi2 (reducedChi2)
712-730 E19.15 --- bicCG12 ? Bayesian information criterion value of
the CG12 model (bic_CG12)
732-748 E17.13 --- bicCG12E1 ? Bayesian information criterion value of
the CG12E1 model (bic_CG12E1)
750-767 E18.14 --- bicCG12E2 ? Bayesian information criterion value of
the CG12E2 model (bic_CG12E2)
769-786 E18.14 --- bicCG1 ? Bayesian information criterion value of
the CG1 model (bic_CG1)
788-804 E17.13 --- bicCG1E1 ? Bayesian information criterion value of
the CG1E1 model (bic_CG1E1)
806-824 E19.15 --- bicCG2 ? Bayesian information criterion value of
the CG2 model (bic_CG2)
826-843 E18.14 --- bicCG2E2 ? Bayesian information criterion value of
the CG2E2 model (bic_CG2E2)
845-864 E20.15 --- bicCE ? Bayesian information criterion value of
the CE model (bic_CE)
866-892 F27.18 --- bicC Bayesian information criterion value of
the C model (bic_C)
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Note (1): Two-Gaussian models used to describe eclipsing binary light curve
geometries.
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Model Description Nb of parameters in the model
------------------------------------------------------------------------------
- Two eclipses
CG12 Without ellipsoidal-like var. 7
CG12E1 With ellipsoidal-like var. on eclipse 1 8
CG12E2 With ellipsoidal-like var. on eclipse 2 8
------------------------------------------------------------------------------
- One eclipse
CG Without ellipsoidal-like var. 4
CGE With ellipsoidal-like var. on eclipse 1 5
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- No eclipse
CE Ellipsoidal-like var. 3
C Constant 1
------------------------------------------------------------------------------
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Acknowledgements:
Nami Mowlavi, Nami.Mowlavi(at)unige.ch
(End) Patricia Vannier [CDS] 26-May-2017