Fritz Zwicky Prize for Astrophysics & Cosmology

Professor Ewine van Dishoeck is Professor of molecular astrophysics at Leiden University, the Netherlands and external scientific member of the Max Planck Institute for Extraterrestrial Physics. After a MSc in theoretical quantum chemistry; she obtained her PhD in astrochemistry in 1984 from the Leiden University, and held positions at Harvard, Princeton and Caltech before returning to Leiden in 1990. From 2007-2021, she was the scientific director of the Netherlands Research School for Astronomy (NOVA), and since 2009, she is co-Editor of Annual Reviews of Astronomy and Astrophysics. From 2018-2021, van Dishoeck served as the President of the International Astronomical Union (IAU). She has received several prestigious awards, including the 2000 Dutch Spinoza Prize, the 2015 Albert Einstein World Award of Science, the 2018 Kavli Prize for Astrophysics and two ERC Advanced grants. She is a Member or Foreign Associate of several academies, including that of the Netherlands, USA, Germany and Norway.

Prof. van Dishoeck has devoted her career to understanding how these molecules shape the Universe around us. With her unique and comprehensive approach encompassing quantum chemical calculations, laboratory studies, and astronomical modelling and observations, she has pioneered and led the field of astrochemistry and revolutionized our understanding of the physical processes leading to the formation of stars and planets by studying the trail of molecules from star-forming clouds to protoplanetary disks.

A big mystery in the early days of astrochemistry was how large molecular clouds could exist in space when the ultraviolet parts of stellar light can easily destroy them. Prof. van Dishoeck's famous and much-cited PhD thesis showed how abundant molecules like molecular hydrogen and carbon monoxide (CO) could protect the interior of a cloud through a process called &ldquot;self-shielding&rdquot;. This research led to several seminal papers on the chemical structure of diffuse interstellar clouds.

Prof. van Dishoeck has frequently exploited cutting-edge observational facilities, especially in the infrared and (sub-)millimetre wavelength ranges. She pioneered mid-infrared spectroscopy in star-forming interstellar clouds and discovered the presence of key organic molecular species locked in ices on grains. Her research revealed that icy grains are effective factories of pre-biotic organic molecules, ensuring that these species are present in significant amounts when terrestrial planets are formed.

Prof. van Dishoeck and her teams have studied in detail the formation and evolution of protostellar disks with ground and space state-of-the-art observatories at submillimeter and infrared wavelengths, tracing in particular the path of water from interstellar clouds, via collapsing cores, to planet-forming disks. Her masterful application of spectroscopic tools across a broad range of wavelengths, with a superb exploitation of the most capable astronomical measurement techniques, and increasingly powerful theoretical modelling have brought the goal of understanding the formation of solar systems many steps closer.

She led the Leiden Laboratory for Astrophysics from 1992-2005, in which experiments are conducted to simulate the chemical processes in and on icy grain mantles. She now leads the development of sophisticated physical-chemical models of gas-phase and gas-grain chemistry from the small to large scales, linking the observations and basic processes.

In addition to her groundbreaking scientific work, Prof. van Dishoeck has been an active and vital member of the astronomical community. As president of the International Astronomical Union, she led the celebrations for its centenary in 2019; the more than 5000 public and scientific activities reached millions of people worldwide. She also co-curated that year an exhibition on Cosmos: Art & Knowledge. She has been a strong advocate for a number of large billion-Euro ground and space-based observational facilities that push the studies of the molecular universe to unprecedented levels. These include ALMA and the Herschel and MIRI/JWST satellites. Her science vision, leadership, and political skills enabled her to play key roles in all phases of these projects. The trust that the community has in her judgement is also apparent from her memberships of the deciding bodies of ESA and review committees of top astronomical research institutes.

Her unique and high impact research has made Ewine van Dishoeck the leading and most influential observational astrochemist in the world, as demonstrated her citation numbers: over 670 published papers, cited nearly 50,000 times, with an h-index of 115, one of the highest of the entire astronomical community.

Professor Sir Martin Rees (Lord Rees of Ludlow, Astronomer Royal of England, past President of the Royal Society and Master of Trinity College) studied in Cambridge University taking a BA in 1963 and PhD (1967), the latter for work with Dennis Sciama on physics of quasars and tests of steady state cosmology. After several research posts, and then a Chair at the University of Sussex, he was appointed Plumian Professor in Cambridge in 1973, post he held until 1991. He has held visiting and professorial positions in London, Princeton, Sussex, Harvard, and Caltech, where he interacted collegially with Zwicky in Fritz's home and office during his visit to Caltech in1971. Rees held, at last count 25 honorary doctorates from universities around the world and honorary fellowships and awards in 13 countries. He has been a member of the Order of Merit since 2007. The most recent of his 10 books 'On the Future' is being translated into 16 languages.

Prof. Martin Rees has maintained a consistent flow of important papers, over an amazingly wide range of topics in astronomy and cosmology-especially in high-energy processes, compact objects, relativistic astrophysics, galactic evolution, and the emergence of structure in the expanding universe. He is widely admired for his physical insight, and many of his ideas have proved prescient, being vindicated by later observations, forming the basis for productive development by many others. He is primarily a theorist, but has always maintained close interactions with observers in all wavebands. He has achieved his pervasive influence not only through his papers, but also through his students, postdocs, the extended international 'network' of collaborators, the many lectures and reviews, both at conferences and to more general public audiences. He has also, especially in the last two decades, had an important role in science policy and international collaborations. 

Prof. Rees has been the most influential single contributor to our understanding of the nuclei of galaxies. Even in the 1960s while still a student, he made predictions about 'superluminal expansion'; and other physical processes now recognised to be crucial to these phenomena. He originated key ideas about supermassive black holes - how the holes form, generate collimated jets, and energise active galaxies, their multiphase gaseous environment, and their use as probes of relativistic gravity.

With colleagues and students, he has maintained a flow of original contributions to the study of compact objects. Early in his career, he helped delineate the now-standard scenario for X-ray binaries in terms of accretion onto compact objects. More recently, his focus has been on gamma-ray bursts, where he and his associates have injected several key ideas that have clarified how these enigmatic objects arise.

He has focused not only on the cores of galaxies, but also on the galaxies themselves, and wrote classic papers that related the characteristic sizes of galaxies to basic physics. He authored some key papers on 'cold dark matter' (CDM) in the 1980s; later, he pioneered the exploration of CDM's implications for the 'first stars', high-redshift quasars, the ionisation and structure of the intergalactic medium. Over 40 years ago, he was already emphasising the importance of exploring 'how the cosmic dark age ended' and of 'Population III' stars.

In recent years there has been enormous growth in interest in the high-redshift universe. Prof. Rees has emphasized the role of molecules in early cooling, the role of successive mergers in the coordinated build-up of galaxies and massive black holes and the use of gamma-ray burst and supernovae to probe early epochs. He was the first to propose the possibility of 'cosmic tomography' using the 21 cm line, a subject now attracting wide interest in the context of future radio-astronomy projects. As a first-year postdoc in 1968, he wrote a prescient paper proposing that cosmic microwave background polarisation measurements could elucidate the origin of fluctuations and anisotropy in the microwave background. Polarisation of the CMB was first detected in 2002 and is now accepted as a key diagnostic for the physics of ultra-early eras. Another type of CMB fluctuation, the 'Rees-Sciama' effect due to large non-linear perturbations, was also proposed back in 1968, and is attracting renewed interest. He has been associated with many key developments in understanding gamma-ray bursts. His pioneering 1988 paper on the tidal disruption of stars by massive black holes (TDEs) led to this topic being intensively studied, at least 60 such events having been observed. In addition, Prof. Rees has written influential papers on large-scale clustering in the universe; cosmic magnetic fields and their origin; gravitational radiation; and cosmic strings, the idea of multiple Universes and the future of mankind itself.

Prof. Rees is one of the most highly cited researchers in his field. His influence on the contemporary development of astronomy and astrophysics - via informal discussions, correspondence, his wide travels, many lectures, and reviews is even greater than appears the formal publication record.