This proposal aims to help illuminate the circulation of matter and energy out of galactic disks and into their surrounding halos. We observe, in galactic halos, not only hot gas (temperatures of about 10 million Kelvin), but also cool gas, cosmic-ray particles with velocities near the speed of light, and magnetic fields. In a wide variety of galaxies with relatively high star-formation rates, the hot gas seems to be pushing the cool gas outward over scales many times the size of the host galaxy. How much of the matter in the halo will actually escape the galaxy’s gravity, and how much will fall back, impacting the galaxy? This proposal examines that question by building a semi-analytic model of outflow dynamics that combines the various components mentioned above (hot gas, cool gas, cosmic rays, and magnetic fields), which will be used to compare to observations of the kinematics of cool gas. In this way, we will improve our understanding of wind dynamics, and estimate the fraction of gas that escapes a variety of galaxies.
|Effective start/end date||12/1/12 → 6/30/14|
- National Science Foundation (AST-1346755)