What's lighting up the Magellanic Stream?
Abstract
Galaxy interactions have greatly disturbed and redistributed the gas in the Magellanic System throughout the halo of the Milky Way. Using the Wisconsin H-α Mapper (WHAM) telescope, we have completed the highest sensitivity and kinematically resolved emission-line survey of the entire Magellanic Stream. These observations enable us to determine how the ionization conditions change over 100 degrees across the sky, including the region below the South Galactic Pole. We explore the sources of that ionization and find that photoionization from the Milky Way and Magellanic Clouds is insufficient to explain the observed H-α emission. We further investigate whether halo-gas interactions, self ionization through a "shock cascade" that results as the Stream plows through the halo, and energetic processes associated with the Milky Way's center could be responsible for the ionization. The gas in the Magellanic Stream could supply enough gas to maintain or even boost the star formation in the Milky Way, but only if it can survive the journey to the Galaxy's disk.
- Publication:
-
American Astronomical Society Meeting Abstracts #234
- Pub Date:
- June 2019
- Bibcode:
- 2019AAS...23412401B