Master Thesis Defense by Oliver Damkjær

The defence is held online via zoom. See guidelines and information here. 

Supervisor: Marianne Vestergaard
External supervisor: Hans Kjeldsen 

Title: A study of molecular gas in nearby active galactic nuclei with Atacama Pathfinder EXperiment, APEX

Abstract: I present CO(2-1) and CO(3-2) global emission line observations of 17 nearby active galactic nuclei (AGN), carried out with the 230 GHz APEX-1 and 345 GHz APEX-2 receivers on the Atacama Pathfinder EXperiment (APEX) telescope. The main goal of this project is to probe the molecular gas content of galaxies with an actively accreting supermassive black hole in the center, to determine the physical properties and the kinematics of the molecular gas.  I develop a simple toy model of the gas structure and kinematics of a typical spiral galaxy and investigate to what degree the kinematics of the molecular gas can be constrained through a forward modelling approach. I evaluate the performance of the model using the Affine Invariant Markov Chain Monte Carlo (MCMC) Ensemble sampler emcee. From my analysis of the gas motions using MCMC, I find that a simple model such as this is capable of producing emission line profiles similar to that we see in the data, and expect to see from theoretical considerations of the kinematics of rotating gas in disk galaxies.