Galactic archaeology in and around the Milky Way
PhD ceremony: Ms. E. Starkenburg, 11.00 uur, Aula Academiegebouw, Broerstraat 5, Groningen
Dissertation: Galactic archaeology in and around the Milky Way
Promotor(s): prof. E. Tolstoy, prof. A. Helmi
Faculty: Mathematics and Natural Sciences
There is much to be learnt from our own “cosmological backyard”: Only in our own Milky Way and some surrounding galaxies we can resolve and observe individual stars and learn from them about galaxies in general. Because stars keep a chemical fingerprint during their lives and also preserve kinematical information for long times, studying the present-day stars can teach us about the past.
In this thesis we discuss various topics in this area of Galactic archaeology. In one of our projects, we look for substructures in position and velocity space in the outer halo of the Milky Way. These can be remnants of disrupted dwarf galaxies, victims from a process called “cosmic cannibalism”. We find several substructures and deduce that at least 10%, but perhaps the whole halo of the Milky Way is built up from disrupted smaller galaxies.
Subsequently we focus on the study of the smaller satellite galaxies that (still) survive the gravitational forces from the much bigger Milky Way they orbit. A surprising result from earlier work was that no very primitive stars were found in these small galaxies. We show however that these stars are present. Further study of the chemical elements in the atmosphere of some of these primitive stars shows that these match better the (equivalent) population of stars in the Milky Way than the dominant population of stars in dwarf galaxies. We also model the formation and evolution of satellite galaxies and find that many of the observed properties can be well reproduced in our model.
Last modified: | 13 March 2020 01.12 a.m. |
More news
-
02 July 2024
Start EngD programmes Autonomous Systems and Sustainable Process Design
In September, the Engineering Doctorate (EngD) programmes Autonomous Systems and Sustainable Process Design will start at the Faculty of Scfience and Engineering.
-
25 June 2024
Heineken Young Scientists Award for Casper van der Kooi
For his research in the field of Natural Sciences, Casper van der Kooi will receive the Heineken Young Scientists Award.
-
24 June 2024
Measuring stickiness
Several plant species use tiny sticky droplets to attract and trap insects. These droplets form an ideal toxin-free insecticide that could be easily washed off of edible plants. Abinaya Arunachalam built a tool to measure the stickiness of...