Max Planck Institute for Astrophysics

With twelve Synergy Grants, the Max Planck Society claims top spot in the ERC ranking

A thought experiment investigates what would happen if a tiny primordial black hole were to sit at the center of the sun

The James Webb Telescope reveals extremely distant objects

Computer simulations show that binary stars produce a large amount of this vital element

Asifa Akhtar and Volker Springel are honoured with the 2021 Leibniz Prize of the German Research Foundation

Dark matter and dark energy determine how the universe looks. But that is pretty much all cosmologists know about these phenomena. Their nature is still completely unclear. While they cannot be directly observed, a team led by Volker Springel at the Max Planck Institute for Astrophysics in Garching is simulating how this mysterious matter and enigmatic energy have influenced the development of space, which has brought further insights about their properties as well as other aspects.

Supernovae portend cosmic catastrophes. When a massive star slides into an energy crisis at the end of its life, or a sun that has already died is overfed with matter, the end is an explosion of unimaginable proportions. What exactly happens here? Hans-Thomas Janka from the Max Planck Institute for Astrophysics in Garching wants to get down to the nuts and bolts. He simulates supernovae on the computer and makes them explode in the virtual world – meanwhile even in three dimensions.

Gravitational waves are some of the most spectacular predictions of the 1915 general theory of relativity. However, it wasn’t until half a century later that physicist Joseph Weber attempted to track them down. In the early 1970s, Max Planck scientists also began working in this research field, and developed second-generation detectors. The groundwork laid by these pioneers meant the waves in space-time ceased to be just figments of the imagination: in September 2015 they were finally detected.

They are some of the most exotic objects in space: neutron stars. Incredibly dense and only 20 kilometers across, they rotate about their axes at breakneck speed, emitting cones of radiation out into space in the process. Some of these cosmic beacons have particularly strong magnetic fields. Michael Gabler from the Max Planck Institute for Astrophysics in Garching studies these magnetars – and so learns a thing or two about their nature.

It is a superlative brain, and has a somewhat boastful name to reflect this: SuperMuc. “Muc” refers to Munich, which isn’t entirely correct, with the more than 100-ton computer being located outside the city limits of the Bavarian capital – in a 500-square-meter hall of the Leibniz Supercomputing Centre on the campus in Garching.

Dark matter, which makes up more than 80 percent of the mass in the universe, neither absorbs nor emits light and interacts with light and normal (baryonic) matter only through its gravity. The nature of dark matter is one of the most important open questions in astrophysics and cosmology. A theoretical model for dark matter, called "Fuzzy Dark Matter" (FDM), imprints a characteristic signature on the light that is bent around a massive galaxy (a so-called gravitational lens). By analyzing a gravitational lens system observed in the radio range with extremely high angular resolution, we have determined how "fuzzy" dark matter can be.

Recent observations have revealed that the first quasars are often surrounded by bright, giant nebulae. These span up to several 100,000 light years, about ten times larger than the quasar host galaxy. According to new detailed computer simulations of galaxy evolution performed at MPA, the observed extended nebulae can be explained as quasar light that reflects off surrounding cool neutral hydrogen clouds. Crucially, this mechanism only works if the energy provided by the quasar is able to produce gigantic galactic winds that blow out large masses of gas from its immediate vicinity. 

In 2020, a tantalizing hint of new physics violating “parity symmetry” was found in polarization data of the cosmic microwave background obtained with the Planck satellite at high frequencies. Based on the Planck data and a simplified assumption about the impact of the polarized dust emission in the Milky Way, the scientists reported a violation of the symmetry of the laws of physics under inversion of spatial coordinates with 99.2% confidence level. 

13 billion years ago, the radiation of the first galaxies transformed the Universe, ionizing the hydrogen between galaxies in a process called cosmic reionization. Despite their intimate connection, the formation of the first galaxies and the reionization process are typically studied separately. A team led by an MPA researcher has now produced the first suite of simulations that simultaneously capture these processes, as well as their connection, called THESAN.

Intermediate-mass black holes (IMBH) should be linking stellar black holes and supermassive black holes, but their formation mechanisms are uncertain. Young massive star clusters (SCs) are promising environments for the formation of such objects. An international team led by MPA researchers, has realized realistic simulations of SCs, where these missing links form by stars - black holes mergers.