Research

General Strategy

NOVA's scientific program is based on three multiply-connected inter-university networks, built around key researchers with international reputations, who lead groups in their respective institutions, and who already have ongoing collaborations. In addition, the NOVA Board and Scientific Director are key researchers who actively participate in the networks.

Network 1:	Formation and evolution of galaxies: from high redshift to the present
Network 2:	Formation and evolution of stars and planetary systems
Network 3:	The astrophysics of black holes, neutron stars and white dwarfs

Each network has a coordinator (PI), selected from the key researchers, and appointed for five years.
Each network organizes regular meetings where key researchers, their teams, and other NOVA researchers discuss and coordinate their work in progress. This has proven an effective way to exchange ideas and to start new collaborative efforts between groups of researchers.

Inter-university cooperation is traditionally strong in Dutch astronomy; the composition of teams of key researchers for each of the three networks from different universities ensures that this tradition will be continued during the coming decade.

Network 1: Formation and evolution of galaxies: from high redshift to the present

Prof. Dr. P.D. Barthel	RuG
Prof. Dr. M. Franx(coordinator)	UL
Prof. Dr. J.M. van der Hulst	RuG
Dr. L. Koopmans	RuG
Prof. Dr. K. Kuijken	UL
Dr. S.S. Larsen	UU
Prof. Dr. R. Peletier	RuG
Dr. H.J.A. Röttgering	UL
Dr. J. Schaye	UL
Prof. Dr. E.Tolstoy	RuG

Galaxies contain billions of stars, as well as interstellar gas and dust, and are embedded in dark halos of unknown constitution. Astronomers are able to look back in time, by observing galaxies at ever greater distances. Because light travels at finite velocity, distant objects are seen at a time when the Universe was young. The expansion of the Universe causes light to be redshifted, so that the most distant galaxies are those with the highest redshift. How did galaxies form? What processes have occurred between high redshift and the present? Do evolved galaxies contain relics which are clues to their formation? What are the influences of the environment, of nuclear activity, and of the original large-scale distribution of dark matter? What is the role of massive black holes in galactic nuclei?

Network 2: Formation and evolution of stars and planetary systems

Prof. Dr. E.F van Dishoeck	UL
Dr. M. Hogerheijde	UL
Prof. Dr. C.U. Keller	UU
Dr. A. de Koter	UvA
Prof. Dr. M. Spaans	RuG
Prof. Dr. L.B.F.M. Waters (coordinator)	UvA

New stars continue to be born deep inside molecular clouds in galaxies. The birth process leads to a circumstellar disk of gas and dust from which planets and comets may subsequently form. What are the physical processes that lead to these new solar systems, and how do they evolve? How is the chemical composition of the gas and dust involving the major biogenic elements modified during the collapse from the cold, tenuous interstellar medium to the dense protoplanetary material? What is the nature of exo-planets orbiting other stars? Massive stars are important in driving the chemical evolution and energetics of the interstellar medium in galaxies. Do massive stars form in a similar way as solar type stars, and are they capable of forming planetary systems? How important are chemical composition, rotation and mass loss for the evolution of massive stars?

Network 3: The astrophysics of black holes, neutron stars and white dwarfs

Prof. Dr. A. Achterberg	UU
Prof. Dr. H. Falcke (coordinator)	RU
Prof. Dr. P. Groot	RU
Prof. Dr. L. Langer	UU
Prof. Dr. M. van der Klis	UvA
Dr. S. Portegies Zwart	UvA
Prof. Dr. F. Verbunt	UU
Prof. Dr. R.A.M.J. Wijers	UvA
Dr. R. Wijnands	UvA

At the end of its life, a massive star explodes and ejects its outer layers. The stellar core collapses to form a neutron star or a black hole. These are the densest objects that exist, and the ones with the strongest gravitational fields. What are the properties of matter at the extreme density in the interior of a neutron star? What are the observational signatures of black holes? Can we observationally verify the extraordinary predictions of General Relativity for the properties of curved space-time near these objects? How do particles and radiation behave near these compact objects? What happens when two compact objects orbiting each other eventually merge? Is this the origin of the most powerful explosions we know, the enigmatic gamma-ray bursts?