The Villa

In the past, the directors of the observatory and their families lived in this building. Today, however, the villa hosts working groups researching extragalactic and theoretical astrophysics.

Extragalactic astrophysics is the study of the Universe beyond our galaxy, the Milky Way. Some of the most important research topics are the formation of galaxies and the role of giant black holes residing in the centre of galaxies. Another research field within extragalactic astronomy is that of galaxy clusters. These are the biggest astronomical objects in the Universe and can provide a wealth of information on the physics of plasmas, the origin of cosmic magnetic fields and gravity. Researchers in the villa also actively search for dark matter.

As part of theoretical astrophysics, scientists create models of stellar and planetary atmospheres with the help of supercomputers. By comparing the models with the results of observations, astrophysicists can draw conclusions concerning the conditions on the surfaces of stars and planets. Hoping to find life on planets similar to the Earth, the scientists have a special interest in planets of distant solar systems (exoplanets).

 

Fig. 1: The brightest radio sources in the sky at frequencies near the FM band (150 MHz). Images taken by the LOFAR telescope.

Fig. 2: Simulation of magnetic fields in the Universe, tracing the filamentary distribution of matter. Massive galaxy clusters emerge in the nodes. The illustrated section measures many millions of light years across.

Fig. 3: Model of the atmosphere of an extrasolar giant gas planet. The parent star is located on the left of the planet (outside the picture). The blue shroud originates from the blue light of the star, which the planet´s atmosphere reflects towards us. The reddish light illustrates the self-radiation of the planet.

 

Simulations in Astrophysics

Today, supercomputers are crucial for studying the complex processes and systems in the Universe. They help the astronomers create increasingly detailed models and verify the predictions based on these models by observations from large modern telescopes. We can understand the conditions of the Universe only with the help of such models.

Astrophysicists calculate the physical structure (temperature, pressure and chemical composition) of stars and exoplanets (e.g. extrasolar gas planets) with computer simulations. In this way, the scientists can screen the atmospheres of exoplanets and measure the concentration of oxygen. These 3D simulations demand immense computing power. Processing a typical model of a gas planet requires 100 hours on 2.5 million CPU cores.  In the villa, scientists design the programs for these calculations. Subsequently, the programs run on the most powerful supercomputers in the world and send the results back to our observatory for analysis.

Complex simulations performed on supercomputers are also required in the field of Extragalactic astrophysics. With their help, the astronomers in Hamburg investigate the origin of cosmic magnetic fields, the indirect signals of dark matter and high-energy phenomena occurring near black holes.

Fig. 1: Model of the solar atmosphere. Result of the 3D radiation transport calculation for a model of the gas streams (convection) in the outer zones of the Sun.

Fig. 2: Simulation of the formation of cold, compact clouds (illustrated in red) in a hot wind coming from galaxies producing many new stars. These simulations help understand the distribution of chemical elements and magnetic fields in the Universe.