J/ApJ/898/46 NIR LCs of RRab stars from the VVV survey (Dekany+, 2020)
Near-infrared search for fundamental-mode RR Lyrae stars toward the inner bulge
by deep learning.
Dekany I., Grebel E.K.
<Astrophys. J., 898, 46 (2020)>
=2020ApJ...898...46D 2020ApJ...898...46D
ADC_Keywords: Stars, variable; Photometry, infrared
Keywords: RR Lyrae variable stars; Light curve classification; Neural networks;
Near infrared astronomy; Catalogs; Surveys
Abstract:
Aiming to extend the census of RR Lyrae stars to highly reddened
low-latitude regions of the central Milky Way, we performed a deep
near-IR variability search using data from the VISTA Variables in the
Via Lactea (VVV) survey of the bulge, analyzing the photometric time
series of over a hundred million point sources. In order to separate
fundamental-mode RR Lyrae (RRab) stars from other periodically
variable sources, we trained a deep bidirectional long short-term
memory recurrent neural network (RNN) classifier using VVV survey data
and catalogs of RRab stars discovered and classified by optical
surveys. Our classifier attained a ∼99% precision and recall for light
curves with signal-to-noise ratio above 60, and is comparable to the
best-performing classifiers trained on accurate optical data. Using
our RNN classifier, we identified over 4300 hitherto unknown bona fide
RRab stars toward the inner bulge. We provide their photometric
catalog and VVV J,H,Ks photometric time series.
Description:
We analyzed near-IR photometric time series of the VVV survey
(Minniti+ 2010NewA...15..433M 2010NewA...15..433M), acquired between 2010 and 2015. Our
target area encompasses the inner bulge region at low Galactic
latitudes consisting of the VVV fields b299-b304 and b308-b382,
spanning across -10°≲l≲+10.5° and -2.5°≲b≲+3.8°.
Every field was observed at 100 epochs in the Ks band and at two
epochs in the J and H bands of the VISTA photometric system with a
nonuniform cadence, except for the fields b308-b310, which have
several hundred epochs in Ks.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 95 13250 Coordinates and basic photometric properties
of the RRab stars
table4.dat 44 2382903 Photometric time-series of the RRab stars
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See also:
II/348 : VISTA Variable in the Via Lactea Survey DR2 (Minniti+, 2017)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
II/364 : VIRAC. The VVV Infrared Astrometric Catalogue (Smith+, 2019)
J/A+A/312/111 : [Fe/H] from RR Lyrae light curves (Jurcsik+, 1996)
J/A+A/475/1159 : Supervised classif. of variable stars (Debosscher+, 2007)
J/AcA/61/1 : VI light curves of Galactic Bulge RR Lyrae (Soszynski+, 2011)
J/ApJS/203/32 : Machine-learned ASAS Classif. Cat. (MACC) (Richards+, 2012)
J/ApJS/213/9 : Catalina Surveys periodic variable stars (Drake+, 2014)
J/AcA/64/177 : VI light curves of Galactic Bulge RR Lyrae (Soszynski+, 2014)
J/ApJ/821/L25 : Bulge RR Lyrae RV Assay (BRAVA-RR) (Kunder+, 2016)
J/AcA/66/405 : Gal. bulge eclipsing & ellipsoidal binaries (Soszynski+, 2016)
J/AJ/153/204 : RR Lyrae stars from the PS1 3π survey (Sesar+, 2017)
J/AcA/67/297 : OGLE Galactic center Cepheids and RR Lyrae (Soszynski+, 2017)
J/ApJ/863/79 : RR Lyrae cand. in the Galactic Center (Contreras Ramos+, 2018)
J/ApJ/857/54 : JHKs photometry of VVV RR Lyrae stars (Dekany+, 2018)
J/ApJ/869/82 : Carnegie-Chicago Hubble Program: RR Lyrae obs. (Rich+, 2018)
J/other/ApSS/363.127 : Bulge RR Lyrae VVVDR4 photometry (Majaess+, 2018)
J/A+A/622/A60 : Gaia DR2 misclassified RR Lyrae list (Clementini+, 2019)
J/ApJ/883/58 : Cepheids from VVV in southern Gal. midplane (Dekany+, 2019)
J/MNRAS/484/4833 : Oosterhoff dichotomy in Galactic bulge (Prudil+, 2019)
J/other/Sci/365.478 : Milky Way classical Cepheids sample (Skowron+, 2019)
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- ID [1/13250] Object identifier
7- 8 I2 h RAh [17/18] Hour of Right ascension (ICRS)
10- 11 I2 min RAm Minute of Right ascension (ICRS)
13- 17 F5.2 s RAs Second of Right ascension (ICRS)
19 A1 --- DE- [-] Sign of the Declination (ICRS)
20- 21 I2 deg DEd [18/40] Degree of Declination (ICRS)
23- 24 I2 arcmin DEm Arcminute of Declination (ICRS)
26- 29 F4.1 arcsec DEs Arcsecond of Declination (ICRS)
31- 38 F8.6 d Per [0.28/0.98] Pulsation period
40- 45 F6.3 mag Ksmag [12/16.3] Magnitude of intensity mean
in VISTA Ks-band
47- 51 F5.3 mag TotAmp [0.05/0.7] Total (peak-to-valley) Ks-band
amplitude
53- 53 I1 --- Ap [1/4] Optimal photometric aperture;
see Section 3.2
55- 59 F5.1 --- S/N [30.4/522] Signal-to-noise ratio
in Ks-band light curve
61- 65 F5.3 --- Prob [0.5/1]? Classification probability score
67- 85 I19 --- GaiaDR2 ? Gaia DR2 (I/345) source identifier
87- 91 I5 --- OGLE ? OGLE source identifier
( in Simbad)
93- 95 A3 --- Comm Source remark flag (1)
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Note (1): Comment as follows:
v = visual classification (102 occurrences);
C18 = object listed by Contreras Ramos+ 2018, J/ApJ/863/79
(<[CMG2018] bNNN NNN NNNNNN> in Simbad; 405 occurrences)
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 I5 --- ID [1/13250] Object identifier
7- 18 F12.6 d HJD [55272.3/57934.1] Observation day;
HJD-2400000.0
20- 21 A2 --- Filt VISTA photometric passband (J, H or Ks)
23- 28 I6 --- Pawprint [253/928304] Identifier (1)
30- 31 I2 --- Chip [1/16] Number of the VIRCAM chip
33- 38 F6.3 mag mag [11.86/19.53] Apparent magnitude in Filt
40- 44 F5.3 mag e_mag [0.003/0.4] Error in mag
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Note (1): Of the corresponding VISTA pawprint (single detector image stack),
identical to the value of the "HIERARCH ESO DET EXP NO" ESO header
keyword in the CASU photometric catalog.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 16-Nov-2021