Wolfgang Hillebrandt - Biography#

Prof. Hillebrandt graduated in 1969 from the University of Köln and obtained his PhD at the same university in 1973. He passed the Habilitation in 1977 at the TH (now TU), Darmstadt. He had been working since 1973, as a Research Associate, at the Institut für Kernphysik of the TH, where he remained until 1978. His research field, then, was the physics of neutron stars and also nuclear reactions in the astrophysical context, with modeling of the r-process (rapid neutron captures) for the nucleosynthesis of the heavy elements.

In 1978, Hillebrandt moved to the MPI für Physik und Astrophysik, Institut für Astrophysik (first in München and later in Garching). There he headed from the start a research group in the field of supernovae and nucleosynthesis that has become the strongest in the world. One of his strenghts was, from the very beginning, the modeling of the gravitational collapse of massive stars that gives rise to one of the two classes of supernova explosions. They not only modeled the collapse of nonrotating stellar cores, but also the more realistic case of initially rotating cores. In that, the group was leading the way and it has never lost its supremacy. Work on the equation of state of matter at very high densities (a continuation of that started by Hillebrandt in Darmstadt) was also very important. Work on the processes of nucleosynthesis in novae had also begun.

When the explosion of SN 1987A (in February that year) came, Hillebrandt's group was first in the interpretation and modeling of the wealth of new data that this very nearby supernova provided. Well before that, Hillebrandt had already become an authority in the field, giving invited review talks at every supernova meeting. Also at this epoch, work had started on the production of gravitational waves by stellar collapse, and Hillebrandt had initiated the series of international workshops on Nuclear Astrophysics, held semiannually at the Ringberg Castle (now at their XVII edition).

With the reunification of Germany, there was a reorganization of the Max-Planck Institutes, and there were projects to eliminate the MPI für Astrophysik. Hillebrandt, as Acting Director from 1991-94, vigorously and successfully opposed such move. On his initiative, the Institute changed its structure, to be run by an international and very strong team of directors, rotating as Managing Directors. Hillebrandt became on of those directors in1997.

At the beginning of the 90's, Hillebrandt became increasingly interested in the physics of thermonuclear supernovae. By the middle of the decade, he had become a leader in the field. That was based on a much deeper knowledge of the complex process of propagation of thermonuclear flames than was current at the time. It provided a new basis for the subsequent numerical simulations, in which the Garching group was almost unique already. Research on thermonuclear supernovae (the Ia-type) has become extremely important from their use as calibrated candles in cosmology for discovering the accelerated expansion of the universe. Hillebrandt promoted and led the European Research Training Network on the Physics of Type Ia Supernova Explosions (2002-2006), which brought together the main theoretical and observational European groups in the field.

The group led by Hillebrandt in Garching has achieved a dominant position, internationally, in supernova research. Its work is the main reference in the topics of deflagration-to-detonation transition in superrnova explosions, the different explosion mechanisms, and the multidimensional hydrodynamic simulations of the outbursts. The work includes nucleosynthesis and the prediction of the light curves and of the spectra of the light emitted in those events. It has been extended to the planning, centralization and analysis of observations made at different observatories, building on the experience gained in the RTN.

Prof. Hillebrandt has published over 450 papers, most of them in the main international journals of his field. The 10 papers listed in Part 2 are representative of the general impact of his publications. He has also published several books and supervised a large number of PhD theses, many of them by people who have afterwards become leading scientists. Countless postdocs have benefited from his knowledge and expertise.