The VMC survey -IX. Pilot study of the proper motion of stellar populations in the LMC from 2MASS and VISTA data

Abstract

We use multi-epoch near-infrared observations from the VISTA survey of the Magellanic Cloud system (VMC) to measure the proper motion of stars of the LMC, in one tile of 1.5 deg^2 centred at (alpha, delta) = (05:59:23.136, -66:20:28.68) and including the South Ecliptic Pole, with respect to their 2MASS position over a time baseline of ~10 years and from VMC observations only, spanning a time range of ~1 year. Stars of different ages are selected from the (J-Ks) vs. Ks diagram and their average coordinate displacement is computed from the difference between Ks band observations for stars as faint as Ks=19 mag. Proper motions are derived by averaging up to seven 2MASS-VMC combinations in the first case and from the slope of the best fit line among the seven VMC epochs in the second case. Separate proper motion values are obtained for variable stars in the field. The proper motion of ~40,000 LMC stars in the tile, with respect to ~8000 background galaxies, obtained from VMC data alone, is mu_alpha cos(delta) = +2.20+/-0.06 (stat) +/-0.29 (sys) and mu_delta = +1.70+/-0.06 (stat) +/-0.30 (sys) mas/yr. This value agrees with recent ground-based determinations in a nearby field but is larger than studies with the HST; the cause of this discrepancy may be due to additional systematic errors in the data. The LMC proper motion is also clearly distinct from the proper motion derived for stars of the Milky Way. The relative proper motion between the foreground stars and the LMC stars is ~5 mas/yr. Furthermore, we measure a decrease of the proper motion with increasing logarithm of stellar age for LMC stars. This study, based on just one VMC tile, shows the potential of the 2MASS-VMC and VMC-VMC combinations for a comprehensive investigation of the proper motion across the Magellanic system. (Abridged)

16 pages, 18 figures, accepted for publication in Astronomy & Astrophysics

References in corpus (5)

• The VISTA Science Archive
• AGB stars in the Magellanic Clouds. II. The rate of star formation across the LMC
• The Space Motion of Leo I: Hubble Space Telescope Proper Motion and Implied Orbit
• The Magellanic Quasars Survey. III. Spectroscopic Confirmation of 758 AGNs Behind the Magellanic Clouds
• The VMC Survey - X. Cepheids, RR Lyrae stars and binaries as probes of the Magellanic System's structure

Cited by in corpus (19)

• VIRAC: The VVV Infrared Astrometric Catalogue
• Red Supergiant Stars as Cosmic Abundance Probes: KMOS Observations in NGC 6822
• The star formation history of the Magellanic Clouds derived from long-period variable star counts
• The VMC Survey -- XXXIV. Morphology of Stellar Populations in the Magellanic Clouds
• The VMC survey XXX. Stellar proper motions in the central parts of the Small Magellanic Cloud
• The VMC survey -- XLI. Stellar proper motions within the Small Magellanic Cloud
• The VMC survey - XVII. The proper motion of the Small Magellanic Cloud and of the Milky Way globular cluster 47 Tucanae
• The origin of dust extinction curves with or without the 2175 A bump in galaxies: The case of the Magellanic Clouds
• New quasars behind the Magellanic Clouds. Spectroscopic confirmation of near-infrared selected candidates
• The intrinsic reddening of the Magellanic Clouds as traced by background galaxies -- I. The bar and outskirts of the Small Magellanic Cloud
• Identification of AGN in the XMM-Newton X-ray survey of the SMC
• The VMC survey XXVIII. Improved measurements of the proper motion of the Galactic globular cluster 47 Tucanae
• The VMC survey -- XLV. Proper motion of the outer LMC and the impact of the SMC
• The VMC survey
• The VMC survey -- LIV. The internal kinematics of the LMC with new VISTA observations
• Time-Series Surveys and Pulsating Stars: The Near-Infrared Perspective
• The VMC survey -- LIII. Data release #7. Complete survey data and data from additional programmes
• The orbital dynamics of the LMC and SMC about the Milky Way
• The VMC survey -- XLVI. Stellar proper motions in the centre of the Large Magellanic Cloud