THIRD-EPOCH MAGELLANIC CLOUD PROPER MOTIONS. II. THE LARGE MAGELLANIC CLOUD ROTATION FIELD IN THREE DIMENSIONS

By R. P. van der Marel, N. Kallivayalil. 2013

168 citations recorded by the source corpus.

We present the first detailed assessment of the large-scale rotation of any galaxy based on full three-dimensional velocity measurements. We do this for the LMC by combining our Hubble Space Telescope average proper motion (PM) measurements for stars in 22 fields, with existing line-of-sight (LOS) velocity measurements for 6790 individual stars. We interpret these data with a model of circular rotation in a flat disk. The PM and LOS data paint a consistent picture of the LMC rotation, and their combination yields several new insights. The PM data imply a stellar dynamical center that coincides with the H i dynamical center, and a rotation curve amplitude consistent with that inferred from LOS velocity studies. The implied disk viewing angles agree with the range of values found in the literature, but continue to indicate variations with stellar population and/or radius. Young (red supergiant) stars rotate faster than old (red and asymptotic giant branch) stars due to asymmetric drift. Outside the central region, the circular velocity is approximately flat at Vcirc = 91.7 ± 18.8 km s−1. This is consistent with the baryonic Tully–Fisher relation and implies an enclosed mass M(8.7 kpc) = (1.7 ± 0.7) × 1010 M☉. The virial mass is larger, depending on the full extent of the LMC's dark halo. The tidal radius is 22.3 ± 5.2 kpc (24.°0 ± 5.°6). Combination of the PM and LOS data yields kinematic distance estimates for the LMC, but these are not yet competitive with other methods.

Subfields: Astronomy and Astrophysics, Education, Instrumentation

View Paper: https://www.semanticscholar.org/paper/b86e8032894a30d52ccadd50ceac7b197e97dc65

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Citations in the corpus

Hunting for the Dark Matter Wake Induced by the Large Magellanic Cloud (2019, methodology): “Rotation Curve: van der Marel & Kallivayalil (2014) derived the rotation curve of the LMC using HST proper motions of 22 stars with known line-of-sight velocities.”
The Local Group on FIRE: dwarf galaxy populations across a suite of hydrodynamic simulations (2018, methodology): “Specifically, we adopt the H Ibased rotation curve for the SMC from Stanimirović, StaveleySmith & Jones (2004) and the proper motion-based rotation curve for the LMC from van der Marel & Kallivayalil (2014).”
A timing constraint on the (total) mass of the Large Magellanic Cloud (2015, methodology): “Application of the Tully-Fisher (1977) relation to the peak velocities of the SMC and LMC measured by Stanimirović et al. (2004) and van der Marel & Kallivayalil (2014), respectively, yields MSMC/MLMC ∼ (60kms−1/90kms−1)4 ∼ 0.2.”
The total mass of the Large Magellanic Cloud from its perturbation on the Orphan stream (2018, methodology): “For each mass, we fix the scale radius so that the mass enclosed at 8.7 kpc matches the measured value of 1.7 × 1010 M from van der Marel & Kallivayalil (2014).”