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.
Current research at MPA
Modified gravity models often contain some form of screening to reduce to general relativity in our immediate cosmic neighbourhood. Scalar waves from astrophysical or cosmological events were thought to significantly disrupt this screening of the Solar System, invalidating previously viable modified gravity models. MPA scientists show that disruptions are actually generally negligible for physically relevant setups.
Neutron stars are the densest objects in the Universe; however, their exact characteristics remain unknown. Using recent observations and simulations, an international team of scientists including researchers at the Max Planck Institute for Astrophysics (MPA) has managed to narrow down the size of these stars. Thus the scientists were able to exclude a number of theoretical descriptions for the neutron star matter.