Searching for the LMC Corona: the Missing Element for the Formation of the Magellanic Stream
Abstract
The Magellanic Clouds are connected to an extended tail of neutral and ionized gas known as the Magellanic Stream. The Stream's mass, morphology, spatial extent and metallicity cannot be fully explained by current numerical simulations, which assume tidal interactions or ram-pressure stripping as the origin mechanism. Preliminary results from new hydrodynamical simulations suggest that the existence of a warm corona around the LMC significantly affects the formation of the Stream; these simulations may for the first time be able to explain both the Stream's large ionized gas mass and the existence of its Leading Arm. A warm corona is motivated by the LMC's high mass and by the detection of interstellar CIV absorption in the spectra of hot stars in the LMC. To test and validate the warm-corona hypothesis, we propose to analyze 30 archival HST/COS spectra of AGN at LMC impact parameters between 3 and 35 kpc to determine the extent and properties of the LMC corona. Using measurements of SiIV and CIV absorption, we will derive the corona's size, density profile, ionization state, and temperature, which is crucial to constrain our modeling of the Magellanic system. This archival analysis offers the potential to solve the 50-year enigma of the origin of the Magellanic Stream.
- Publication:
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HST Proposal
- Pub Date:
- June 2020
- Bibcode:
- 2020hst..prop16363D