The VMC survey. XXX. Stellar proper motions in the central parts of the Small Magellanic Cloud

F. Niederhofer*, M.-R. L. Cioni, S. Rubele, T. Schmidt, K. Bekki, R. de Grijs, J. Emerson, V. D. Ivanov, M. Marconi, J. M. Oliveira, M. G. Petr-Gotzens, V. Ripepi, J. Th. van Loon, S. Zaggia

*Corresponding author for this work

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

We present the first spatially resolved map of stellar proper motions within the central (~3.1 × 2.4 kpc) regions of the Small Magellanic Cloud (SMC). The data used for this study encompasses four tiles from the ongoing near-infrared VISTA survey of the Magellanic Clouds system and covers a total contiguous area on the sky of ~6.81 deg 2. Proper motions have been calculated independently in two dimensions from the spatial offsets in the K s filter over time baselines between 22 and 27 months. The reflex motions of approximately 33 000 background galaxies are used to calibrate the stellar motions to an absolute scale. The resulting catalog is composed of more than 690 000 stars which have been selected based on their position in the (J - K s, K s) color-magnitude diagram. For the median absolute proper motion of the SMC, we find (μ αcos(δ), μ δ) = (1.087 ± 0.192 (sys.) ± 0.003 (stat.), -1.187 ± 0.008 (sys.) ± 0.003 (stat.)) mas yr -1, consistent with previous studies. Mapping the proper motions as a function of position within the SMC reveals a nonuniform velocity pattern indicative of a tidal feature behind the main body of the SMC and a flow of stars in the south-east moving predominantly along the line-of-sight.

Original languageEnglish
Article numberL8
Number of pages4
JournalAstronomy and Astrophysics
Volume613
DOIs
Publication statusPublished - 31 May 2018

Keywords

  • proper motions
  • surveys
  • galaxies: individual: SMC
  • Magellanic Clouds
  • stars: kinematics and dynamics

Cite this