Stars exploding as supernovae are the main sources of heavy chemical elements in the Universe. Using elaborate computer simulations, a team of researchers from the MPA and RIKEN in Japan were able to explain the recently measured spatial distributions of radioactive titanium and nickel in Cassiopeia A. The computer models yield strong support for the theoretical idea that such stellar death events can be initiated and powered by neutrinos escaping from the neutron star left behind at the origin of the explosion.
With complex radiation-hydrodynamical simulations scientists at MPA demonstrate that “pre-supernova feedback” by the intense radiation and stellar winds from massive O and B type stars changes the multi-phase structure of the interstellar medium. While the efficiency of star formation is reduced by “pre-supernova feedback”, individual supernovae explode in lower density environments with enhanced impact.
It is widely known that our planet Earth and the Solar System itself are embedded in the Milky Way, and it is through this galaxy that we look out onto the Universe. Our Galaxy’s gravitational field and its non-uniformity limit the accuracy of astrometric observations of distant – extragalactic – objects. An international group of astrophysicists including a researcher at the Max Planck Institute for Astrophysics tried to find out how strong this effect is.
Researchers at MPA and in other institutions worldwide devised a new way of simulating the impact of large-scale primordial perturbations in the dark matter distribution on the abundance of structures observed at late times, the so-called separate universe simulations. Using this technique, the MPA researchers recently obtained some of the most precise measurements of the local bias, confirming the known trend that more massive halos are more biased than smaller halos.
Researchers using the Atacama Large Millimeter/submillimeter Array (ALMA) successfully imaged a radio “hole” around a galaxy cluster 4.8 billion light-years away. This is the highest resolution image ever taken of such a hole caused by the Sunyaev-Zel'dovich effect (SZ effect). The image proves ALMA’s high capability to investigate the distribution and temperature of gas around galaxy clusters through the SZ effect.
In collaboration with researchers from the USA, MPA scientists have mounted a series of ambitious experiments that use a combination of quasar absorption-line spectra, neutral hydrogen line data, and state-of-the-art cosmological hydrodynamical simulations to probe the interface between galaxies and their surrounding gaseous environment. The researchers found that galaxies with gas-rich disks are embedded within gas-rich halos and that the gas in these halos is distributed smoothly and relatively isotropically.
Supernovae are extremely bright stellar explosions – superluminous supernovae are even brighter. In a new study, MPA researchers present their simulations of superluminous supernova spectra months and even years after the outbreak and show that they are very similar to gamma-ray bursts, another type of highly energetic explosions. In addition, the results point to very high masses of oxygen and magnesium, suggesting very massive progenitor stars.
By using galaxies as giant gravitational lenses, an international group of astronomers including researchers at the MPA have made an independent measurement of how fast the Universe is expanding. The newly measured expansion rate for the local Universe is consistent with earlier findings - but in intriguing disagreement with measurements of the early Universe. This hints at a fundamental problem at the very heart of our understanding of the cosmos.
Professor Rashid Sunyaev, Director of the Max Planck Institute for Astrophysics, received the State Prize of the Russian Federation in Science and Technology jointly with Nikolay Shakura, professor of astrophysics at Moscow State University, for their seminal 1973 paper "Black holes in binary systems. Observational appearance".
During a scaling workshop end of May at the Leibniz-Rechenzentrum, Matteo Bugli from MPA won the Leibniz Scaling Award. He was able to produce the best relative improvement with his ECHO code for three-dimensional simulations of relativistic magnetized accretion disks orbiting around black holes.