Anne-Marie Weijmans - home page


Name      : Anne-Marie Weijmans
Adress    : Dunlap Institute for Astronomy & Astrophysics
            50 St. George Street
            Toronto, ON
	    Canada M5S 3H4
Telephone : +1 416 946 5432
E-mail    :
Room      : 205

Slides for Dark Matter 101

 Dark Matter 101, DI Summer Student Lecture Series 2012


My research concentrates on the structure and evolution of galaxies, and more specifically, on the properties of their dark matter haloes. The dark halo is the most massive component of a galaxy, and plays an important role in the formation and evolution of that galaxy. Even though dark matter is not visible (it does not interact with the electro-magnetic force), we can infer its presence from the gravitational influence that it has on its surroundings: stars and gas will move faster in the presence of a dark matter halo than they would if the dark matter were not there. I therefore use integral-field spectrographs such as
SAURON and VIRUS-P, to measure the movements of stars and gas in the faint outskirts of galaxies, where the influence of the dark matter is strongest. Based on these kinematics, I map the dark halo using dynamical modeling techniques. And because integral-field spectrographs not only captures the kinematics of the stars, but also their chemical properties, I can at the same time determine the properties (age, metallicity) of the stellar halo population. The galaxies that I study in this way are part of the Atlas3D sample of nearby early-type galaxies

The figure on the left illustrates what I'm attempting to achieve with my research: I start out with observations, which I use to make models of dark matter haloes. The properties of these dark haloes can then be compared with predictions of theoretical simulations, which can then trigger new predictions that we can test with observations.

More recently, I have also started to look at galaxies at higher redshift. I work with students here in Toronto to compare the structural properties of nearby galaxies with those of galaxies far away (at higher redshifts). Because light has a finite speed, the light of these last galaxies takes billions of years to reach us, and therefore we see these galaxies at a time when they were very young. By comparing these young galaxies to the old ones that we see today, we can learn something about which processes galaxies have undergone over time, and how that changed their appearances.

Main Publications

-  On the shapes and structures of high-redshift compact galaxies,
M. Chevance, A. Weijmans, I. Damjanov, R.G. Abraham, L. Simard, S. van den Bergh, E. Caris, K. Glazebrook, 2012, ApJ, 754L, 24

-  Dissecting the Lyman Alpha emission halo of LAB1,
A. Weijmans, R.G. Bower, J.E. Geach, A.M. Swinbank, R.J. Wilman, P.T. de Zeeuw, S.L. Morris, 2010, MNRAS, 402, 2245

-  Stellar velocity profiles and line strengths out to four effective radii in the early-type galaxies NGC 3379 and NGC 821,
A. Weijmans, M. Cappellari, R. Bacon, P.T. de Zeeuw, E. Emsellem, J. Falcon-Barroso, H. Kuntschner, R.M. McDermid, R.C.E. van den Bosch, G. van de Ven, 2009, MNRAS, 398, 561

-  The shape of the dark matter halo in the early-type galaxy NGC 2974,
A. Weijmans, D. Krajnović, G. van de Ven, T.A. Oosterloo, R. Morganti & P.T. de Zeeuw, 2008, MNRAS, 383, 1343--1358

And my PhD thesis can be found here:  
The Structure of Dark and Luminous Matter in Early-Type Galaxies.

Popular articles

-  SAURON ziet alles...,
A. Weijmans, Eureka!, november 2008, edition 23 (in Dutch)

-  SAURON - het oog dat alles ziet,
A. Weijmans & D. Krajnović, Zenit, september 2005, p392--395 (in Dutch)

Education and Public Outreach

I am the coordinator of the DI summer student program, which offers undergraduate students an opportunity to work with staff members and postdocs on research projects in observational and instrumentational astronomy. The program also includes a lecture series, and workshops to improve research and communication skills.

There are many outreach activities and opportunities at the DI and DAA: see our website Here you can book planetarium and telescope tours, as well as book public speakers. You can find me on this list for talks on The Quest for Dark Matter, as well as The Lives of Galaxies.

Dutch Astronomy Olympiad

I was involved in organising the first Dutch Astronomy Olympiad in 2007. This Olympiad offers high school students a chance to enlarge their knowledge on astronomy, and win a trip to the Observatory of La Palma!
The Astronomy Olympiad has become an annual event. Have a look at Sterrenkunde Olympiade for more information.


I play the oboe, and was a member of the North Toronto Community Band. Also, have a look at the webpages of the orchestras in the Netherlands where I played the oboe and the cor anglais:

Sinfonietta Voorschoten
Randstad Quintet (links to YouTube video)
Leidse Harmoniekapel