Universe and Galaxy Evolution

Arif Babul, Douglas Rennehan, Fabrice Durier and Belaid Moa

Our team studies how the various components of the universe--gas, dark matter, stars and galaxies--evolved into what they are today. We test theories about the origins of galaxies--such as our own Milky Way galaxy--as well as groups of galaxies and massive clusters of galaxies using powerful supercomputers that can simulate the progression of the universe since the Big Bang, and replicate its nearly 14 billion-year-old history. Since the beginning of human civilization we have been wondering how the universe came into being, how and when stars were born, and how life evolved. It's a fascinating riddle that we enjoy working on.

The aim of our research programme is not only to understand how the dark matter coalesces to form discreet structure, but also to develop physical insights into what happens to the gas and galaxies as this process unfolds.

Arif Babul
Arif Babul (Distinguished Professor)

Douglas Rennehan
Douglas Rennehan (Ph.D. Candidate)

Fabrice Durier
Fabrice Durier (Former Post-Doc)

Belaid Moa
Belaid Moa (Compute Canada, WestGrid)

We will list these very soon...

Douglas Rennehan
Douglas Rennehan

Email: douglas dot rennehan at gmail dot com



In the last five years we have simulated several models using gadget and gizmo. The data and the results will be shared with the rest of the community very soon...

To account for the subgrid effects, we have incorporated LES into Gizmo. Instead of relying on the Smagorinsky–Lilly constant model, we implemented Germano dynamic model.

black hole dynamics is now being incorporated into our dynamic diffusion model.

Galaxies have many properties. Here are a few that we found interesting...


Romulus Simulation

GIF showing the Romulus simulation results

Protocluster Simulation

GIF showing the formation of a protocluster


One of the projects we looked at is the presence of cold gas clouds (log(T)<=4) in the CGM.

3x Splitting

Cold Gas in CGM using 3x Splitting

Cold Gas Clouds formed by Splitted Particles

Cold Gas in CGM using 3x Splitting and splitted particles only

Dynamic Splitting

Cold Gas in CGM using dynamic Splitting

Cold Gas Clouds formed by Splitted Particles

Cold Gas in CGM using dynamic splitting and splitted particles only.

Cold Gas Clouds formed with No Splitting

Cold Gas in CGM with no splitting.

One of the projects we looked at is the presence of cool gas clouds (log(T)<4.6) in the CGM.

3x Splitting

Cool Gas in CGM using 3x Splitting

Cool Gas Clouds formed by Splitted Particles

Cool Gas in CGM using 3x Splitting and splitted particles only

Dynamic Splitting

Cool Gas in CGM using dynamic Splitting

Cool Gas Clouds formed by Splitted Particles

Cool Gas in CGM using dynamic splitting and splitted particles only.

Cool Gas Clouds formed with No Splitting

Cool Gas in CGM with no splitting.

One of the projects we looked at is the presence of warm gas clouds (log(T)<5) in the CGM.

3x Splitting

Warm Gas in CGM using 3x Splitting

Warm Gas Clouds formed by Splitted Particles

Warm Gas in CGM using 3x Splitting and splitted particles only

Dynamic Splitting

Warm Gas in CGM using dynamic Splitting

Warm Gas Clouds formed by Splitted Particles

Warm Gas in CGM using dynamic splitting and splitted particles only.

Warm Gas Clouds formed with No Splitting

Warm Gas in CGM with no splitting.