The Birth and Evolution of Galaxies

Website archive 1995-2013

Victoria Centre is part of the national Royal Astronomical Society of Canada, which is dedicated to bringing information about astronomy to the general public.

Advanced Search


Image Gallery
Online Articles
Observing Highlights




Time Machines, Cannibalism and Chemical Pollution

Dr Puragra Guhathakurta (Raja)
HIA Herzberg Fellow

March 12, 2003
University of Victoria, Elliott Building, Room 061

Galaxies are basic entities in the Universe. The question of how galaxies form and evolve over time is one of the most important open questions in modern cosmology.

Two complementary approaches to studying galaxy formation and evolution:


The "direct look-back method" relies on the fact that looking at very distant galaxies also implies that we are looking at them as they were in the distant past. In that sense, telescopes are time machines that take us back into the history of our Universe.


The "fossil record method" relies on the fact that the present-day properties of galaxies around us bear subtle clues about past processes that have sculpted them into being. The merging and cannibalism of galaxies is an important process in shaping galaxies. A significant observable clue is the degree to which a galaxy has been "polluted" with heavy elements (iron, calcium, carbon, magnesium, etc) formed in previous generations of stars.

This multi-media presentation (computer animation/video/poster) will contain the latest results of observations carried out with the twin 10-meter Keck telescopes, the world's largest optical telescopes, and the Hubble Space Telescope. A technique called "adaptive optics" is revolutionizing optical astronomy, and there will be a brief demonstration of this technique.

Raja's website:

Astronomy: Galaxies, Time, and Light - download the 4Mb PowerPoint presentation file

Astronomy: Galaxies, Time, and Light - run the presentation in your web browser - requires JavaScript-capable browser

Hint: Click on the "Slide Show" icon to be found at the bottom right of the browser window to get a full screen slide show.  Tap your spacebar to advance the slide show in sequence (be patient - wait for the next image to download!).  Hit the "Esc" key at any time to get your browser window back.

� 2014 Royal Astronomical Society of Canada, Victoria Centre
All text and images are Copyright their respective owners
Victoria Centre adheres to our National Privacy Policy
Website: - Contact us

RASC Victoria Centre does not endorse nor is responsible for the content of external websites. External links will open in a new window.
Last updated: January 29, 2014

The Royal Astronomical Society of Canada is dedicated to the promotion of astronomy and its related sciences; we espouse the scientific method, and support dissemination of discoveries and theories based on that well-tested method.

Web hosting & email services provided by Matthew Watson