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Paper: |
Disk Destruction and (Re)-Creation in the Magellanic Clouds |
Volume: |
480, Structure and Dynamics of Disk Galaxies |
Page: |
27 |
Authors: |
Nidever, D. L. |
Abstract: |
Unlike most satellite galaxies in the Local Group that have long lost
their gaseous disks, the Magellanic Clouds are gas-rich dwarf galaxies
most likely on their first pericentric passage allowing us to study disk
evolution on the smallest scales. The Magellanic Clouds show both
disk destruction and (re)-creation. The Large Magellanic Cloud has a
very extended stellar disk reaching to at least 15 kpc (10 radial
scalelengths) while its gaseous disk is truncated at ∼5 kpc mainly due
to its interaction with the hot gaseous halo of the Milky Way. The
stellar disk of the Small Magellanic Cloud, on the other hand, has
essentially been destroyed. The old stellar populations show no sign
of rotation (being pressure supported) and have an irregular and
elongated shape. The SMC has been severely disturbed by its close
encounters with the LMC (the most recent only 200 Myr ago) which have
also stripped out large quantities of gas creating much of the
Magellanic Stream and the Magellanic Bridge. Amazingly, the SMC has
an intact, rotating HI disk indicating that either the inner HI
was preserved from destruction, or, more likely, that the HI disk
reformed quickly after the last close encounter with the LMC. |
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