J/A+A/674/A170 OGLE-IV eclipsing binaries residual light curves (Adam+, 2023)
Variable stars in the residual light curves of OGLE-IV eclipsing binaries
towards the Galactic Bulge.
Adam R.Z., Hajdu T., Bodi A., Hajdu R., Szklenar T., Molnar L.
<Astron. Astrophys. 674, A170 (2023)>
=2023A&A...674A.170A 2023A&A...674A.170A (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Stars, variable ; Photometry ; Optical
Keywords: methods: numerical - binaries: close - binaries: eclipsing -
stars: variable: general - techniques: photometric
Abstract:
The Optical Gravitational Lensing Experiment (OGLE) observed around
450000 eclipsing binaries (EBs) towards the Galactic Bulge.
Decade-long photometric observations such as these provide an
exceptional opportunity to thoroughly examine the targets. However,
observing dense stellar fields such as the Bulge may result in blends
and contamination by close objects.
We searched for periodic variations in the residual light curves of
EBs in OGLE-IV and created a new catalogue for the EBs that contain
'background' signals after the investigation of the source of the
signal.
From the about half a million EB systems, we selected those that
contain more than 4000 data points. We fitted the EB signal with a
simple model and subtracted it. To identify periodical signals in the
residuals, we used a GPU-based phase dispersion minimisation python
algorithm called cuvarbase and validated the found periods with
Lomb-Scargle periodograms. We tested the reliability of our method
with artificial light curves.
We identified 354 systems where short-period background variation was
significant. In these cases, we determined whether it is a new
variable or just the result of contamination by an already catalogued
nearby one. We classified 292 newly found variables into EB, δ
Scuti, or RR Lyrae categories, or their sub-classes, and collected
them in a catalogue. We also discovered four new doubly eclipsing
systems and one eclipsing multiple system with a δ Scuti
variable, and modelled the outer orbits of the components.
Description:
In this paper we present an alternative and fast method for
searching for periodic variations in residuals of EB LCs.
First, we chose an appropriate sample based on the characteristics of
the dataset and selected the EB systems that were suitable for our
analysis. Then, we subtracted the signals of the EBs and searched for
periodicities in the residual LCs using PDM and LS methods. In the
following step, we selected our candidates and classified them via a
visual inspection of their LCs, with the use of Fourier parameters and
with an image-based machinelearning classifier. We validated our
method through tests with artificial LCs as well.
As a result, we find 354 systems that have significant periodic
variations in their residual LCs. Of them, 62 are caused by already
known blended variables, but in most cases (292) we find a new
variable measured together with the EB.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 40 62 Eclipsing binary systems whose photometry contains
a signal of a known background variable
tablec1.dat 30 292 Results of image-based classification for the
background variables
tableb1.dat 76 292 Eclipsing binary systems with a new variable in
the background
lc/* . 292 Individual residual light curves (table 4)
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See also:
J/AcA/66/405 : Galactic bulge eclipsing & ellipsoidal binaries
(Soszynski+, 2016)
https://www.astrouw.edu.pl/ogle/ogle4/OCVS/blg/ecl : OGLE Home Page
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- Name1 OGLE-IV ID of the binary
21- 40 A20 --- Name2 OGLE-IV ID of known background variable
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Byte-by-byte Description of file: tablec1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- Name OGLE-IV ID of the binary
21- 30 A10 --- Type Most probable variability type (1)
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Note (1): The best variability type when its probability was greater than 80%,
and the two with the highest scores otherwise.
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Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- Name OGLE-IV ID of the binary
21- 29 F9.6 d Per1 Orbital period of the binary
31- 39 F9.6 d Per2 Orbital period of the background variable
41- 45 A5 --- Type Variability subtype of the background variable
47- 76 A30 --- FileName Name of the light curve file in subdirectory lc
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Byte-by-byte Description of file: lc/*
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Bytes Format Units Label Explanations
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1- 10 F10.5 d HJD Heliocentric Julian date (HJD-2450000)
11- 19 F9.3 mag Imagres Residual I magnitude
21- 25 F5.3 mag e_Imagres rms uncertainty on Imagres
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Acknowledgements:
Rozalia Adam, adam.rozalia(at)csfk.org
(End) Patricia Vannier [CDS] 27-Apr-2023