University Of Tasmania

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The 3D kinematics of gas in the small magellanic cloud

journal contribution
posted on 2023-05-21, 12:51 authored by Murray, CE, Peek, JEG, Di Teodoro, EM, McClure-Griffiths, NM, John DickeyJohn Dickey, Denes, H
We investigate the kinematics of neutral gas in the Small Magellanic Cloud (SMC) and test the hypothesis that it is rotating in a disk. To trace the 3D motions of the neutral gas distribution, we identify a sample of young, massive stars embedded within it. These are stars with radial velocity measurements from spectroscopic surveys and proper motion measurements from Gaia, whose radial velocities match with dominant H I components. We compare the observed radial and tangential velocities of these stars with predictions from the state-of-the-art rotating disk model based on high-resolution 21 cm observations of the SMC from the Australian Square Kilometer Array Pathfinder telescope. We find that the observed kinematics of gas-tracing stars are inconsistent with disk rotation. We conclude that the kinematics of gas in the SMC are more complex than can be inferred from the integrated radial velocity field. As a result of violent tidal interactions with the Large Magellanic Cloud, nonrotational motions are prevalent throughout the SMC, and it is likely composed of distinct substructures overlapping along the line of sight.


Publication title

Astrophysical Journal








School of Natural Sciences


Institute of Physics Publishing, Inc

Place of publication

United States

Rights statement

© 2019. The American Astronomical Society. All rights reserved.

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Socio-economic Objectives

Other information and communication services not elsewhere classified; Expanding knowledge in the physical sciences