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Kinematic Evidence for an Old Stellar Halo in the Large Magellanic Cloud

Dante Minniti·Jura Borissova·Marina Rejkuba·David R. Alves·Kem H. Cook·Kenneth C. Freeman
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Abstract

The oldest and most metal-poor Milky Way stars form a kinematically hot halo, which motivates the two major formation scenarios for our galaxy: extended hierarchical accretion and rapid collapse. RR Lyrae stars are excellent tracers of old and metal-poor populations. We measure the kinematics of 43 RR Lyrae stars in the inner regions of the nearby Large Magellanic Cloud (LMC) galaxy. The velocity dispersion, σ_{true}=53\pm10 km/s, indicates that a kinematically hot metal-poor old halo also exists in the LMC. This suggests that our galaxy and smaller late-type galaxies like the LMC have similar early formation histories.

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Dante Minniti, Jura Borissova, Marina Rejkuba, David R. Alves, Kem H. Cook, Kenneth C. Freeman. 2003-09-12. Kinematic Evidence for an Old Stellar Halo in the Large Magellanic Cloud. https://doi.org/10.1126/science.1088529

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