Degree Year

2024

Document Type

Thesis - Oberlin Community Only

Degree Name

Bachelor of Arts

Department

Physics and Astronomy

Advisor(s)

Bryan Terrazas
Chris Marx

Committee Member(s)

Bryan Terrazas
Jason Stalnaker
Dan Stinebring
Yumi Ijiri

Keywords

Fermi Bubbles, Simulation, Galaxy evolution, Astrophysics, AGN feedback, Active galaxies

Abstract

In 2010, an excess of gamma rays were detected above and below the galactic center by the Fermi Space Telescope, discovered to be caused by two huge plasma lobes named the Fermi bubbles (FBs). It is not known if they are formed by supermassive black hole activity or nuclear star formation, despite several observational campaigns, but more and more evidence suggests the former. In this thesis, we used a modified version of the moving-mesh hydrodynamic code AREPO to simulate four Milky Way-like galaxies with black hole-driven winds over 15 Myr, where we vary the initial wind velocity between 0 − 10000 km s−1 in order to test how wind velocities would affect the physical characteristics of the FBs. In the three active galaxy simulations, AGN winds were enabled from t = 0 − 6 Myr and then turned off. We analyze the spatial distribution of the simulated FBs’ temperature and density. We find that the velocity of the shock front decreases over time, with higher AGN wind speed corresponding to an initially higher, but more rapidly decreasing shock front speed. Additionally, we create mock X-ray maps of the emission assuming most of the X-ray emission comes from thermal bremsstrahlung radiation. Characteristics of simulated bubbles were found to generally agree with observed characteristics of FBs. Significance of model parameters and further model applications are discussed.

Notes

Additional Department: Mathematics

Download

Share

COinS