Cosmic-Ray-driven Outflows from the Large Magellanic Cloud: Contributions to the LMC Filament
Abstract
In this paper, we build from previous work and present simulations of recent (within the past Gyr), magnetized, cosmic-ray driven outflows from the Large Magellanic Cloud (LMC), including our first attempts to explicitly use the derived star formation history of the LMC to seed outflow generation. We run a parameter set of simulations for different LMC gas masses and cosmic-ray transport treatments, and we make preliminary comparisons to published outflow flux estimates, neutral and ionized hydrogen observations, and Faraday rotation measure maps. We additionally report on the gas mass that becomes unbound from the LMC disk and swept by ram pressure into the Trailing Magellanic Stream. We find that, even for our largest outburst, the mass contribution to the Stream is still quite small, as much of the outflow-turned-halo gas is shielded on the LMCs far-side due to the LMCs primarily face-on infall through the Milky Way halo over the past Gyr. On the LMC's near-side, past outflows have fought an uphill battle against ram pressure, with the near-side halo mass being at least a factor of a few smaller than that of the far-side. Absorption-line studies probing only the LMC foreground, then, may be severely underestimating the total mass of the LMC halo formed by outflows.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 2020
- DOI:
- 10.3847/1538-4357/ab7fa3
- arXiv:
- arXiv:1911.02021
- Bibcode:
- 2020ApJ...893...29B
- Keywords:
-
- Large Magellanic Cloud;
- Cosmic rays;
- Galactic winds;
- Magellanic Stream;
- Magnetic fields;
- 903;
- 329;
- 572;
- 991;
- 994;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 23 pages, 13 figures, 2 tables. Accepted to ApJ. See expanded discussion of clustered stellar feedback in Section 3 and clarifications in Figure 3