Near-Infrared Search for Fundamental-mode RR Lyrae Stars Toward the Inner Bulge by Deep Learning

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 Vía Láctea (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.

Accepted for publication in The Astrophysical Journal

References in corpus (11)

• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• The Catalina Surveys Periodic Variable Star Catalog
• Automated supervised classification of variable stars I. Methodology
• A recurrent neural network for classification of unevenly sampled variable stars
• A machine learned classifier for RR Lyrae in the VVV survey
• The VVV Templates Project. Towards an Automated Classification of VVV Light-Curves. I. Building a database of stellar variability in the near-infrared
• On the optimal calibration of VVV photometry
• Into the Darkness: Classical and Type II Cepheids in the Zona Galactica Incognita
• On the Oosterhoff dichotomy in the Galactic bulge: I. spatial distribution
• On the Oosterhoff dichotomy in the Galactic bulge: II. kinematical distribution
• The Carnegie-Chicago Hubble Program: Calibration of the Near-Infrared RR Lyrae Period-Luminosity Relation With HST

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• VVV catalog of ab-type RR Lyrae in the inner Galactic bulge
• The Galactic Bulge exploration IV.: RR~Lyrae stars as traces of the Galactic bar -- 3D and 5D analysis, extinction variation
• Leveraging Deep Learning for Time Series Extrinsic Regression in predicting photometric metallicity of Fundamental-mode RR Lyrae Stars
• A New Period Determination Method for Periodic Variable Stars
• Informative regularization for a multi-layer perceptron RR Lyrae classifier under data shift
• Metallicity estimation of RR Lyrae stars from their I-band light curves