Previous studies of large AGN samples both a low and at high redshifts seemed to rule out galaxy mergers as the drivers for black hole growth. A new technique developed at MPA for selecting a rare type of active galactic nuclei now show that it is possible to identify a new class of AGN in which more than 80% of the galaxies turn out to be merging or interacting systems, with clear indications of an accreting black hole. A detailed statistical analysis then reveals that mergers drive black hole formation in the most massive galaxies in the local Universe.
At the very beginning of the Universe, not only elementary particles and radiation were generated but also magnetic fields. A team of researchers led by the Max Planck Institute for Astrophysics now calculated what these magnetic fields should look like today in the local universe – in great detail and in 3D. Thus, the researchers were able to predict the structure and morphology of the primordial magnetic field in our cosmic neighbourhood for the first time. This field is incredibly weak; nevertheless, the prediction could help to address the challenge of measuring it.
Buoyant bubbles of relativistic plasma in galaxy cluster cores plausibly play a key role in conveying the energy from a supermassive black hole to the intracluster medium (ICM). While the amount of energy supplied by the bubbles to the ICM is set by energy conservation, the physical mechanisms involved in coupling the bubbles and the ICM are still being debated. A team of researchers from the Max Planck Institute for Astrophysics (MPA) and the University of Oxford argues that internal waves might be efficient in extracting energy from the bubbles and distributing it over large masses of the ICM.