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Research Interests
I am fascinated by the questions of how stars and planets form - arguably two of the most exciting and still largely unsolved major problems in contemporary astrophysics. Both of these problems are also major drivers for the question of how and where life originated in the cosmos.

>  Star Formation
I began my research in star formation at Cambridge in the early 1980s through work with Colin Norman on disk winds and the origin of jets in protostellar systems. Since then, I have worked with my students, postdocs and collaborators on many different and important aspects of the general problem of star formation. My research to date has focused on the formation of stars and protostellar disks through gravitational collapse, the origin of jets and outflows from accretion disks around young stars, turbulence and the origin of structure and stars in molecular clouds, the origin of the spectrum of stellar masses (the so-called IMF), the formation of star clusters and globular clusters, the origin of magnetic fields in galaxies, and the origin of globular cluster-forming clouds in the early universe. Hydrodynamics and sometimes hydromagnetic processes are at the heart of much of structure formation in the cosmos, and my work uses these techniques. In addition to theoretical modeling, we do very sophisticated numerical simulations using High Performance Computing facilities provided by SHARCNET.


Useful links
From Darkness to Light: Forming the Oldest Stars in the Cosmos (Press Release)
Astronomers find magnetic Slinky in Orion (Confirmation of torodial magnetic fields, Press Release), and the McMaster press release.


>  Planet Formation
I have extended my research interests into the problem of how planets form and migrate in their natal disks. This is an especially important topic given the discovery of over 250 exosolar Jovian-mass (mainly) planets, most of which orbit very close to their central stars. Planet formation is tightly linked with the process of star formation since both stars and planets form in gaseous protostellar disks which have been observed around all young stars. We have shown how the presence of dead zones in the inner regions of protostellar disks regions of very low disk viscosity can prevent the rapid loss of entire planetary systems by plunging into their central stars via their rapid migration through disks. The interaction of young forming planets with their surrounding gaseous disks is a very important question that is the focus of much of our planetary research.


Useful links
Saving Planetary Systems: Dead Zones to the Rescue (New Scientist)


>  Astrobiology
Related to the origin of stars and planets is another of the most fundamental and exciting problems in science - the origins of life. Astrophysics has a great deal to say about this important question as astronomers begin to search for planets of terrestrial mass (the lowest so far is 5 Earth masses) and learn how to probe the atmospheres of exosolar planets. Meteoritic evidence shows that these bodies are laden with amino acids and other key biomolecules. The Earth's ocean was probably delivered by impacts of meteorites that formed in water-ice rich regions of the early Solar Nebula, at around 2-3 Astronomical Units. Through the OI programs, I have begun working on the question of how processes in protoplanetary disks resulted in the creation of habitable planets complete with their supplies of water and biomolecules.

Please see publications for recent papers, talks, and books I have given or written on these topics. See also our recent book Planetary Systems and the Origins of Life published by Cambridge University Press.

Useful links
Origin of Life on Earth (Leslie E. Orgel)
wapedia: Abiogenesis

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