8 papers
The Formation of Massive Binary Stars
Ian A. Bonnell
The formation of massive stars in close binary systems is complicated due to their high radiation pressure, the crowded environment and the expected minimum separation for fragment…
On the stability of self-gravitating protoplanetary discs
W. K. M. Rice, P. J. Armitage, I. A. Bonnell +1
It has already been shown, using a local model, that accretion discs with cooling times t_cool <= 3 Omega^-1 fragment into gravitationally bound objects, while those with cooling t…
Orbital migration and the brown dwarf desert
Philip J. Armitage, Ian A. Bonnell
The orbital elements of extreme mass ratio binaries will be modified by interactions with surrounding circumstellar disks. For brown dwarf companions to Solar-type stars the result…
The Formation of Massive Stars through Stellar Collisions
Ian A. Bonnell
In this review, I present the case for how massive stars may form through stellar collisions. This mechanism requires very high stellar densities, up to 4 orders of magnitude highe…
Competitive Accretion in Clusters and the IMF
Ian A. Bonnell
Observations have revealed that most stars are born in clusters. As these clusters typically contain more mass in gas than in stars, accretion can play an important role in determi…
Early Evolution of Stellar Clusters
Ian A. Bonnell
Observations have revealed that most stars are born in clusters. These systems, containing from tens to thousands of stars and typically significant mass in gas in the youngest sys…