Donald Lynden-Bell: A Biographical Memoir
  Donald Lynden-Bell's many contributions to astrophysics encompass general
relativity, galactic dynamics, telescope design and observational astronomy. In
the 1960s, his papers on stellar dynamics led to fundamental insights into the
equilibria of elliptical galaxies, the growth of spiral patterns in disc
galaxies and the stability of differentially rotating, self-gravitating flows.
Donald introduced the ideas of `violent relaxation' and `the gravothermal
catastrophe' in pioneering work on the thermodynamics of galaxies and negative
heat capacities. He shared the inaugural Kavli Prize in Astrophysics in 2008
for his contributions to our understanding of quasars. His prediction that dead
quasars or supermassive black holes may reside in the nuclei of nearby galaxies
has been confirmed by multiple pieces of independent evidence. His work on
accretion discs led to new insights into their workings, as well as the
realisation that the infrared excess in T Tauri stars was caused by
protostellar discs around these young stars. He introduced the influential idea
of monolithic collapse of a gas cloud as a formation mechanism for the Milky
Way Galaxy. As this gave way to modern ideas of merging and accretion as
drivers of galaxy formation, Donald was the first to realise the importance of
tidal streams as measures of the past history and present day gravity field of
the Galaxy. Though primarily a theorist, Donald participated in one of the
first observational programs to measure the large-scale streaming of nearby
galaxies. This led to the discovery of the `Great Attractor'. The depth and
versatility of his contributions mark Donald out as one of the most influential
and pre-eminent astronomers of his day.
