Shape of the outer stellar warp in the Large Magellanic Cloud disk

TL;DR

This study reveals an asymmetric, U-shaped stellar warp in the outer LMC disk using Gaia EDR3 data, providing new insights into the galaxy's interaction history with the SMC.

Contribution

It is the first to detect and characterize the NE outer warp of the LMC, confirming its asymmetry and aiding models of the Magellanic system's dynamics.

Findings

Detected a lower amplitude warp in the NE outer LMC disk

Confirmed the warp's asymmetry and U-shape

Provided observational constraints for galaxy interaction models

Abstract

Warps are vertical distortions of the stellar or gaseous disks of galaxies. One of the proposed scenarios for the formation of warps involves tidal interactions among galaxies. A recent study identified a stellar warp in the outer regions of the south-western (SW) disk of the Large Magellanic Cloud (LMC) and suggested that it might have originated due to the tidal interaction between the LMC and the Small Magellanic Cloud (SMC). Due to the limited spatial coverage of the data, the authors could not investigate the counterpart of this warp in the north-eastern (NE) region, which is essential to understanding the global shape, nature, and origin of the outer LMC warp. In this work, we study the structure of the LMC disk using data on red clump stars from the Gaia Early Data Release 3 (EDR3), which cover the entire Magellanic system. We detected a warp in the NE outer LMC disk which is deviated from the disk plane in the same direction as that of the SW outer warp, but with a lower amplitude. This suggests that the outer LMC disk has an asymmetric stellar warp, which is likely to be a U-shaped warp. Our result provides an observational constraint to the theoretical models of the Magellanic system aimed at improving the understanding the LMC-SMC interaction history.