Chad Bustard : A Versatile Family of Galactic Wind Models

Conference: Star Formation, Magnetic Fields, and Diffuse Matter in the Galaxy: A Conference Honoring the Contributions of Richard Crutcher & Carl Heiles, May 23-26, 2016, Madison, WI, USA Website: http://www.astro.wisc.edu/ch16/ Conference Playlist: https://www.youtube.com/playlist?list=PLR0icYcBhA7Rv-QymeskXF15Kd-Mnh_T2 Date: Monday, May 23, 2016 Session: II. Milky Way Galaxy and Surroundings (Chair: Matt Haffner) Speaker: Chad Bustard (University of Wisconsin, Madison) Title: A Versatile Family of Galactic Wind Models Abstract: Current models of galaxy formation overestimate the number of low-mass galaxies and their stellar ages. A possible solution is efficient galactic wind feedback that limits star formation at high redshift in low-mass galaxies. Unfortunately, the processes governing wind feedback are typically at too small scales to be properly accounted for in galaxy formation simulations. I will present a new model of galactic winds aimed at bridging this gap between physically motivated outflow models and cosmological simulations of galaxy formation. The Chevalier and Clegg (1985) galactic wind model is upgraded to include radiative losses, a gravitational potential from an extended mass distribution, and nonuniform mass and energy sources. I will show which wind solutions are most efficient in expelling mass from a galaxy, the abundance of low-temperature high velocity outflows, and the ability of our model, unlike the Chevalier and Clegg model, to reproduce the observed linear relationship between galaxy X-ray luminosity and star formation rate. Additionally, constraining our model to fit this linear trend leads to an inverse relationship between possible wind mass-loading factors and star formation rate. When employed in galaxy formation simulations, this relationship may lead to a better fit to the observed galaxy stellar mass function. Finally, I will address the effects of an extended halo potential on the escape or fall-back of various wind solutions, as well as what happens when outflows form shocks in the intergalactic medium.

Видео Chad Bustard : A Versatile Family of Galactic Wind Models автора Astounding Atomic Antics