Near-Infrared Variability Study of the Central 2.3 arcmin x 2.3 arcmin of the Galactic Centre I. Catalog of Variable Sources

Abstract

We used four-year baseline HST/WFC3 IR observations of the Galactic Centre in the F153M band (1.53 micron) to identify variable stars in the central ~2.3'x2.3' field. We classified 3845 long-term (periods from months to years) and 76 short-term (periods of a few days or less) variables among a total sample of 33070 stars. For 36 of the latter ones, we also derived their periods (<3 days). Our catalog not only confirms bright long period variables and massive eclipsing binaries identified in previous works, but also contains many newly recognized dim variable stars. For example, we found δScuti and RR Lyrae stars towards the Galactic Centre for the first time, as well as one BL Her star (period < 1.3 d). We cross-correlated our catalog with previous spectroscopic studies and found that 319 variables have well-defined stellar types, such as Wolf-Rayet, OB main sequence, supergiants and asymptotic giant branch stars. We used colours and magnitudes to infer the probable variable types for those stars without accurately measured periods or spectroscopic information. We conclude that the majority of unclassified variables could potentially be eclipsing/ellipsoidal binaries and Type II Cepheids. Our source catalog will be valuable for future studies aimed at constraining the distance, star formation history and massive binary fraction of the Milky Way nuclear star cluster.

has been accepted to be published in MNRAS, 64 pages, 26 figures. The complete lists of table 3, 4, 8 and 9 will be published online

References in corpus (15)

• Physical Properties of Wolf-Rayet Stars
• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• An Improved Distance and Mass Estimate for Sgr A* from a Multistar Orbit Analysis
• The structure of the nuclear stellar cluster of the Milky Way
• The Panchromatic Hubble Andromeda Treasury X. Ultraviolet to Infrared Photometry of 117 Million Equidistant Stars
• The old nuclear star cluster in the Milky Way: dynamics, mass, statistical parallax, and black hole mass
• Variability in red supergiant stars: pulsations, long secondary periods and convection noise
• Evidence for a Long-Standing Top-Heavy IMF in the Central Parsec of the Galaxy
• An Improved Model of SiO Maser Emission in Miras
• KMOS view of the Galactic Centre - II. Metallicity distribution of late-type stars
• The period-luminosity relation for type II Cepheids in globular clusters
• Photometric Stellar Variability in the Galactic Center
• A delta Scuti distance to the Large Magellanic Cloud
• Kinematics of classical Cepheids in the Nuclear Stellar Disk
• The Light Curve Shapes as a Key to Resolving the Origin of Long Secondary Periods in Red Giant Stars

Cited by in corpus (8)

• GALACTICNUCLEUS: A high-angular-resolution $JH{K}_s$ imaging survey of the Galactic centre. IV. Extinction maps and de-reddened photometry
• On Socially Distant Neighbors: Using Binaries to Constrain the Density of Objects in the Galactic Center
• Near-Infrared Variability Study of the Central 2.3 arcmin x 2.3 arcmin of the Galactic Centre II. Identification of RR Lyrae Stars in the Milky Way Nuclear Star Cluster
• The Strikingly Metal-Rich Halo of the Sombrero Galaxy
• Mapping the aliphatic hydrocarbon content of interstellar dust in the Galactic plane
• Observations of the 86 GHz SiO maser sources in the Central Parsec of the Galactic Centre
• "Observations" of simulated dwarf galaxies: Star-formation histories from color-magnitude diagrams
• rrlfe: Software for Generating and Applying Metallicity Calibrations for RR Lyrae Variable Stars Across a Wide Range of Phases and Temperatures