Hunstead Lectures 2022: “Our Galaxy in the era of Gaia” by James Binney

James Binney, FRS, FInstP is a renowned British astrophysicist. He is a professor of physics at the University of Oxford and former head of the Sub-Department of Theoretical Physics as well as an Emeritus Fellow of Merton College.

He is a theoretical astrophysicist who has worked principally on the structure and evolution of galaxies. He has built a dynamical model of galaxies both to track intrinsically invisible components (black holes and dark matter) and to understand how galaxies function as machines and were assembled. He has made a number of contributions to areas outside of astrophysics and is the author of six major texts in physics and astrophysics, including the modern-day classic “Galactic Dynamics” with Scott Tremaine.

Binney graduated with a BA from Cambridge University in 1971, and with a doctorate from Oxford University in 1975. From 1975–1979 he was a Fellow by Examination of Magdalen College, Oxford. During 1976 he was a Lindemann Fellow at Princeton University, whither he returned in 1979 as a Visiting Assistant Professor in Astrophysical Sciences. In 1981 he became University Lecturer and in March 1990 Ad Hominem Reader in Theoretical Physics at Oxford University. In July 1996 he became a Professor of Physics at Oxford University. Since 1981 he has been a Fellow and Tutor in Physics of Merton College, Oxford.

He has been a Fellow of the Royal Astronomical Society since 1973 and a Member of the American Astronomical Society since 1976. In 2000 he became a Fellow of the Royal Society of London and a Fellow of the Institute of Physics.

During 1971/2 he was a DAAD Stipendiat at the Albert Ludwigs Univiersitat, Freiburg i. Breisgau. During 1983 he was a Fairchild Distinguished Scholar and the California Institute of Technology. From 1984 – 1993 he was a regular visitor to the Institute of Advanced Study, Princeton, and has been a Visiting Fellow at Princeton University on several occasions. During 1994–7 he was President of both Commission 33 and Division VII of the International Astronomical Union. He is currently a member of the Organizing Committee of Commission 28 of the IAU. He was a member of the Theory Panel of the SERC (1986/8). For PPARC he has served on the Theoretical Research Assessment Panel (1997/9), the Joint Infrastructure Board (1999/2000), the Advanced LIGO oversight Committee (2003–2007), and the Astronomy Grants Panel (2005–2008), as well as several ad-hoc panels.

He has served Nottingham University, Leicester University, University College Dublin, and the Deutsche Forschungs Gemeinschaft as an assessor or review committee member. He has been an external examiner of PhD theses for the Universities of Cambridge, Durham, Edinburgh, Ghent, Goteborg, Leiden, Marseilles, Paris, Princeton, Rutgers, and the Australian National University

He has received a number of awards and honours for his work, including the Maxwell Prize of the Institute of Physics in 1986, the Brouwer Award of the American Astronomical Society in 2003, the Dirac Medal in 2010, and the Eddington Medal in 2013.

With collaborators, he has focused on extracting scientific understanding from observations of galaxies and the gas within and around them. Galaxies are complex machines and the approach taken has been to build simple models that focus on particular aspects of their dynamics and evolution. Early work led to the prediction that elliptical galaxies are not necessarily flattened by rotation, and can be triaxial, and proposed a connection between atomic physics and the characteristic length and mass scales of galaxies. This led to models of the diffuse gas content of clusters of galaxies, and the pioneering of the view that this gas is kept hot by jets shot out by supermassive black holes. Models of hot gas around galaxies like ours led to a picture in which galactic fountains powered by supernovae sustain star formation in many galaxies by cooling circumgalactic gas. Modeling cold gas in our Galaxy led to the conclusion that our Galaxy is barred. Techniques were developed to bring the power of angle-action variables to bear on galactic dynamics. They yielded new chemo-dynamical models of galaxies that are currently being fitted to data from the Gaia satellite and large ground-based surveys of our Galaxy.

During his visit, he spent time interacting with SIfA staff and students and delivered the Hunstead lecture series which explored the following topics:

The past few years have seen major advances in our understanding of the Galaxy with an extraordinary richness in chemical and dynamical space, made possible by ESA Gaia, Kepler, TESS, and an armada of ground-based surveys. Evidence of the first “building blocks” are now beginning to emerge, but what are we to believe? Are we approaching the data in the right way? How are we to compare data to simulations? The vast data sets are beginning to challenge conventional ideas on how to build models of the Galaxy, and how to interpret them. These are some of the themes that will be explored by the speaker.”

Slides and videos of the lectures are available in the links below: