The VMC survey - XXVI. Structure of the Small Magellanic Cloud from RR Lyrae stars

Abstract

We present results from the analysis of 2997 fundamental mode RR Lyrae variables located in the Small Magellanic Cloud (SMC). For these objects near-infrared time-series photometry from the VISTA survey of the Magellanic Clouds system (VMC) and visual light curves from the OGLE IV survey are available. In this study the multi-epoch $K_{\mathrm{s}}$-band VMC photometry was used for the first time to derive intensity-averaged magnitudes of the SMC RR Lyrae stars. We determined individual distances to the RR Lyrae stars from the near-infrared period-absolute magnitude-metallicity ($P{M}_{K_{\mathrm{s}}}Z$) relation, which has a number of advantages in comparison with the visual absolute magnitude-metallicity ($M_V-[Fe/H]$) relation, such as a smaller dependence of the luminosity on interstellar extinction, evolutionary effects and metallicity. The distances we have obtained were used to study the three-dimensional structure of the SMC. The distribution of the SMC RR Lyrae stars is found to be ellipsoidal. The actual line-of-sight depth of the SMC is in the range from 1 to 10 kpc, with an average depth of 4.3 $\pm$ 1.0 kpc. We found that RR Lyrae stars in the eastern part of the SMC are affected by interactions of the Magellanic Clouds. However, we do not see a clear bimodality in the distribution of RR Lyrae stars as observed for red clump (RC) stars.

18 pages, 15 figures, 3 tables. Accepted for publication in MNRAS

References in corpus (17)

• The Gaia mission
• Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties
• The VISTA Science Archive
• New Optical Reddening Maps of the Large and Small Magellanic Clouds
• Clustering of Local Group distances: publication bias or correlated measurements? III. The Small Magellanic Cloud
• The VMC Survey - XIV. First results on the look-back time star-formation rate tomography of the Small Magellanic Cloud
• The VMC Survey. XXV. The 3D structure of the Small Magellanic Cloud from Classical Cepheids
• Clouds, Streams and Bridges. Redrawing the blueprint of the Magellanic System with Gaia DR1
• The RR Lyrae Period - K Luminosity relation for Globular Clusters: an observational approach
• Gaia Data Release 1 - The Cepheid & RR Lyrae star pipeline and its application to the south ecliptic pole region
• New near-infrared period-luminosity-metallicity relations for RR Lyrae stars and the outlook for Gaia
• The VMC Survey. XIII. Type II Cepheids in the Large Magellanic Cloud
• The infrared JHK light curves of RR Lyr
• The VMC survey - XXIII. Model fitting of light and radial velocity curves of Small Magellanic Cloud classical Cepheids
• Eclipsing binary stars in the Large Magellanic Cloud. Results from the EROS-2, OGLE and VMC surveys
• Morphology and metallicity of the Small Magellanic Cloud using RRab stars
• RR Lyrae variables in the Small Magellanic Cloud - II. The extended area: chemical and structural analysis

Cited by in corpus (38)

• A distance determination to the Small Magellanic Cloud with an accuracy of better than 2 percent based on late-type eclipsing binary stars
• Revealing the tidal scars of the Small Magellanic Cloud
• Standard Galactic Field RR Lyrae II: A Gaia DR2 calibration of the period-Wesenheit-metallicity relation
• The VMC Survey -- XXXIV. Morphology of Stellar Populations in the Magellanic Clouds
• High-precision distance measurements with classical pulsating stars
• RR Lyrae variables in Messier 53: Near-infrared Period--Luminosity relations and the calibration using Gaia Early Data Release 3
• The VMC Survey -- XLII. Near-infrared period-luminosity relations for RR Lyrae stars and the structure of the Large Magellanic Cloud
• Magellanic Mayhem: Metallicities and Motions
• The VMC Survey -- XL. Three-dimensional structure of the Small Magellanic Cloud as derived from red clump stars
• Stellar substructures in the periphery of the Magellanic Clouds with the VISTA Hemisphere Survey from the red clump and other tracers
• Carbon stars as standard candles: II. The median J magnitude as a distance indicator
• Evolved Massive Stars at Low-metallicity II. Red Supergiant Stars in the Small Magellanic Cloud
• The VMC survey -- XXXIX: Mapping metallicity trends in the Small Magellanic Cloud using near-infrared passbands
• Multiwavelength Period-Luminosity and Period-Luminosity-Color relations at maximum-light for Mira variables in the Magellanic Clouds
• On Zero Point Calibration of the Red Giant Branch Tip in the Magellanic Clouds
• Ca II Triplet Spectroscopy of Small Magellanic Cloud Red Giants. V. Abundances and Velocities for 12 Massive Clusters
• The VISCACHA survey -- VII. Assembly history of the Magellanic Bridge and SMC Wing from star clusters
• The VMC Survey -- XXXVII. Pulsation periods of dust enshrouded AGB stars in the Magellanic Clouds
• Three-Dimensional Structure and Dust Extinction in the Small Magellanic Cloud
• The VMC Survey -- XXXV. Model fitting of LMC Cepheid light curves
• Application of a Neural Network classifier for the generation of clean Small Magellanic Cloud stellar samples
• The intrinsic reddening of the Magellanic Clouds as traced by background galaxies -- II. The Small Magellanic Cloud
• The intrinsic reddening of the Magellanic Clouds as traced by background galaxies -- I. The bar and outskirts of the Small Magellanic Cloud
• Short period variability in the globular cluster NGC 419 and the SMC field
• Lessons from the Magellanic System and its modeling
• Kinematic complexity around NGC419: resolving the proper motion of the cluster, the Small Magellanic Cloud and the Magellanic Bridge
• Kinematics of stellar substructures in the Small Magellanic Cloud
• On the structure of Small Magellanic Cloud star clusters
• The intrinsic reddening of the Magellanic Clouds as traced by background galaxies -- III. The Large Magellanic Cloud
• Discrete star formation events in the central Bar of the Small Magellanic Cloud
• A Galactic Transformation -- Understanding the SMC's Structural and Kinematic Disequilibrium
• The VMC survey -- LIII. Data release #7. Complete survey data and data from additional programmes
• Distance, reddening and three dimensional structure of the SMC - I: Using RRab stars
• Strömgren photometric metallicity map of the Magellanic Cloud stars using Gaia DR3--XP spectra
• The mass-metallicity relation at z>3 down to M_*= 10^4 M_Sun. A local perspective using the metallicity distribution of RR Lyrae stars
• Peeping into recent star formation history of the Magellanic Clouds
• Revisiting a detached stellar structure in the outer northeastern region of the Small Magellanic Cloud
• Probing the farthest star clusters to the Small Magellanic Cloud