Skip to ContentSkip to Navigation
About us Latest news News News articles

Galactic archaeology in and around the Milky Way

09 December 2011

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.
printView this page in: Nederlands

More news

  • 13 August 2020

    International students discover Groningen in virtual game

    Marketing Groningen is launching an international campaign through which the city is presented to prospective international students of the University of Groningen and Hanze University of Applied Sciences. The campaign is intended to provide...

  • 13 August 2020

    ALMA sees most distant Milky Way look-alike

    Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA), in which the European Southern Observatory (ESO) is a partner, have revealed an extremely distant and therefore very young galaxy that looks surprisingly like our Milky Way....

  • 07 August 2020

    Virus assembly has been filmed

    Scientists in Groningen and Madrid have managed to capture unique images of the first steps of virus assembly. By using a very fast scanning probe microscope, they were able to film how HIV proteins begin to form a virus. It appears that the virus...