Max Planck Institute for Radio Astronomy

New all-sky survey by the MeerKAT radio telescope shows the universe as expected at large distances - unlike previous observations by other telescopes

Event Horizon Telescope advances to submillimeter observations

Ten new neutron stars allow new tests of extreme stellar physics and the theory of relativity

Magnetic fields spiral around the mass monster Sagittarius A* and form up for a restart

The handover of the first dish of the MeerKAT extension signals an important milestone for the SKA-MID construction

Silke Britzen moves between two spheres. As a scientist at the Max Planck Institute for Radio Astronomy, she analyzes the epitome of darkness. That is to say, she studies black holes with telescopes that nearly span the globe. As an artist, she paints pictures bursting with color. Her approach to both research and painting is unorthodox.

The active nuclei of galaxies are among the mightiest powerhouses in the cosmos. They derive their energy from black holes at their centers, which sometimes occur in pairs. In a large-scale campaign, a group led by Stefanie Komossa from the Max Planck Institute for Radio Astronomy in Bonn used several telescopes to peer into the heart of one such energy slingshot.

Sitting deep in the heart of the Milky Way, it is 27,000 light years from Earth and resembles a donut: this is how the black hole at the center of our galaxy looks in the image obtained by researchers using the Event Horizon Telescope (EHT).

Centaurus is one of the most famous constellations in the southern sky. Take a closer look at the constellation through binoculars and you’ll see a pale nebula known as Centaurus A – it is in fact a distant galaxy in which a supermassive black hole resides. Michael Janssen from the Max Planck Institute for Radio Astronomy in Bonn and Radboud University Nijmegen led an Event Horizon Telescope team that has now come closer than ever before to understanding the nature of this gravity trap.

A cosmic lightning storm is playing out all around us. At any given moment, somewhere in the sky, a burst of radiation flashes and then fades away. Only observable with radio telescopes, these bursts last one-thousandth of a second and are one of astrophysics’ greatest mysteries. Scientists rather doubt this is evidence of warlike aliens fighting “star wars” in the vastness of space. Experts have named them “fast radio bursts” – but where do they come from?

By combining two of the most powerful radio telescopes on Earth, an international team of researchers led by the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn, created the most sensitive maps of the radio emission of large parts of the Northern Galactic plane so far. Contrary to previous surveys, GLOSTAR observed not only the radio continuum in the frequency range from 4-8 GigaHertz in full polarization, but simultaneously also spectral lines that trace the molecular gas and atomic gas via radio recombination lines.

This year, we were able to present the first image of the "shadow" of the black hole at the center of our own galaxy, the Milky Way. It is the result of years of data analysis, which began in 2017 with the Event Horizon Telescope and resulted in the first image of such a black hole in the galaxy Messier 87 in 2019. Once again, over 30 employees from all departments of the institute were involved. This image is also a scientific breakthrough. But what makes it special? Why was the data analysis much more challenging than in the case of M87?

2021 marked the fiftieth anniversary of the inauguration of the radio telescope in Effelsberg. In the past decades, the telescope, whose construction broke new technical ground, has produced numerous important observational results. Thanks to constant improvements and renewals it is still state-of-the-art. Selected current observational projects are presented here.

Extremely precise measurements of the motion of a fast-spinning pulsar in a triple star system provide one of the strongest tests ever of a simple, but fundamental prediction of general relativity: that gravity affects all objects with the same acceleration, without regard for their composition, density or the strength of their own gravitational field. General relativity has again survived this test, one of the most stringent ever, which strongly constrains many alternative theories of gravity.

On April 10, 2019, the first image of a black hole was published by a team of 347 international scientists from 59 institutes in 18 countries. Theoretical work and indirect evidence for the existence of black holes has been around for a long time. Only now did the observations provide the necessary resolution for an image made possible by a combination of seven radio telescopes scattered across the Earth, observing the centre of the galaxy M87. More than 30 scientists and engineers of the Max Planck Institute for Radio Astronomy in Bonn are involved in this success.