Exjobbspresentation, Gustav Olander

​AGN impact on the molecular gas reservoir in nearby galaxy NGC 1068 using NH$_3$ as temperature probe
Namn presenterar sitt examensarbete vid masterprogremmet Physics: ”​AGN impact on the molecular gas reservoir in nearby galaxy NGC 1068 using NH$_3$ as temperature probe”, utfört vid institutionen för rymd-, geo- och miljövetenskap. 

Handledare: Mark Gorski
Examinator: Susanne Aalto
Opponent: Oskar Leander & Victor Pettersson

Hybridseminarium, i sal ES53, men du kan också ta del av presentationen via Zoom

​Abstract: 

To understand the evolution of galaxies, it is important understand the properties of the interstellar medium (ISM) and what affects it. When modelling galaxy evolution, star formation rate has shown to be overpredicted without the process of feedback, which prevents star formation. To improve the models of galaxy formation, different feedback processes, e.g. feedback for an Active Galactic Nuclei (AGN), needs to be studied individually. The galaxy NGC 1068 houses a starburst ring at a radius of $\sim3$ kpc and an AGN which have been found to quench star formation up to a kpc-scale around the center. The close distance of 15.5 Mpc makes it possible to resolve different feedback effects in NGC 1068 using the Karl G. Jansky Very Large Array (VLA). Physical conditions in the molecular gas were studied using VLA to probe temperatures using molecular transitions in NH$_3$ as thermometer. Metastable inversion transitions (1,1) through (6,6) were detected presenting a distinct increase in temperature towards the AGN compared to other locations such as bar and spiral arms. A general AGN rotation temperature of $157.0\substack{+78.5 \\ -39.3}$ K was determined while rotation temperatures elsewhere were found to be $\lesssim20-40$ K. The NH$_3$ ortho- to para species ratio towards the AGN suggest the NH$_3$ gas was formed in a cold environment of $\lesssim20$ K. The present day warm environment around the AGN suggests it indeed being the AGN that heats the ISM surrounding it. 

Kategori Studentarbete
Plats: ES53, lecture room, Maskingränd 2, Linsen
Tid: 2021-11-03 11:00
Sluttid: 2021-11-03 12:00

Sidansvarig Publicerad: fr 22 okt 2021.