Current Research Highlights

Hot plasma fills the entire volume of galaxy clusters and makes these objects powerful sources of X-ray radiation. While the density and temperature of this gas can be readily measured, its material properties, such as its viscosity and thermal conductivity are largely unknown. The problem stems from the poorly understood role of weak magnetic fields permeating the gas. While such fields are too weak to directly affect large-scale motions of the gas, they might change the microscopic properties of the plasma. Recent long observations of the Coma cluster in the X-ray band have shown that this is indeed the case – the behavior of the gas is markedly different from expectations for un-magnetized plasma. more

New cosmological simulations targeting the evolution of the first quasars and their host galaxies now follow the effects of radiation from young stars on the interstellar medium. As the international team shows, stellar radiation can alter both the properties of the quasar host galaxy and its satellites, making them more diffuse and less tightly-bound. Satellites are more easily disrupted by the strong tidal forces of the massive central galaxy, which therefore contains a smaller satellite population. more

The Warm-Hot Intergalactic Medium contributes substantially to the matter budget in the Universe – but it is only poorly studied, as it is very difficult to observe. Researchers at MPA have now predicted how it can be explored using heavier elements as tracers. Due to scattering of the cosmic X-ray background some of this line emission can be boosted substantially and should be accessible by the upcoming X-ray survey missions. more

A team of researchers from the Max Planck Institute for Astrophysics, the University Observatory Munich, and collaborators have investigated the effect of heat conduction on the evolution of supernova blast waves and the structure of the supernova-driven interstellar medium (ISM). They find that thermal conduction has a strong impact on the volume filling fractions of cold, warm and hot gas. Thermal conduction also plays an important role for an accurate description of the hot ISM phase structure and the chemical composition of the cold phase of the turbulent ISM. more

For the first time MPA scientists and European collaborators have simulated the solar neighborhood interstellar medium (ISM), including physical processes following all major thermal and non-thermal components - ionized, neutral and molecular gas, dust, interstellar radiation, magnetic fields, and cosmic rays in the presence of star formation. As the different processes strongly influence each other, the simulations highlight the importance of including them all, in particular radiation and cosmic rays, for a realistic model of the star-forming ISM. Within the Gauss Center for Supercomputing (GCS) project SuperSILCC the team will use SuperMUC-NG, one of the world’s fastest supercomputers, to reveal the physical origins of the ISM structure also in extreme environments at high redshift. more

Recent high-resolution microwave and X-ray observations of the galaxy cluster RX J1347-1145 offer a new diagnosis tool of gas motion. Probing different parameters of the hot gas in galaxy clusters, these observations allow the MPA scientists to distinguish between gentle and violent motion of gas stirred by encounters with smaller sub-clusters. more

Models of the large-scale structure of galaxies in the Universe suffer from serious limitations, when artificial boundaries are imposed at the virial radius of the dark matter halo. As MPA scientists demonstrate, environmental effects vary smoothly across the traditionally adopted halo boundary and need to be taken into account even in low-density environments. more

Next generation imaging

February 01, 2019

The Information Field Theory Group at the Max Planck Institute for Astrophysics has released a new version of the NIFTy software for scientific imaging. NIFTy5 generates an optimal imaging algorithm from the complex probability model of a measured signal. Such algorithms have already proven themselves in a number of astronomical applications and can now be used in other areas as well. more

Lately, the impact of magnetic fields in simulations of galaxy formation and evolution is being widely studied. However, it is still unclear to which degree magnetic fields influence the formation and evolution of galaxies. A team of researchers from the astronomical Max Planck Institutes in Garching, the University Observatory in Munich, and the University of Konstanz have introduced a new galactic model with an explicitly modelled circum galactic medium (CGM) to investigate the impact of magnetic fields in an isolated simulation of a Milky Way-like galaxy with the focus on the dynamo amplification of the magnetic field. Further the researchers discuss the possibility of bi-conical magnetic driven outflows and their impact on the star formation rate of the galaxy. more

Astrophysicists at MPA along with an international team of scientists have made a measurement of all the light in the universe, the so-called Extragalactic Background Light (EBL). The EBL is a sea of photons (particles of light) that have been gradually accumulating since the first stars started shining, shortly after the Big Bang. The results are published in Science on November 30th. more

Strong gravitational lensing is an extremely powerful tool to go beyond the current limits in angular resolution and to investigate the high-redshift, i.e. distant Universe. Scientists at MPA take advantage of this phenomenon to perform a detailed study of 17 Lyman-α-galaxies and present an analysis of the sizes and star formation rates of their reconstructed ultra-violet (UV) continuum emission. more

Some stars are observed to rotate with extremely long periods, the ‘slow rotation problem’. A theory developed at MPA now shows how the magnetic field of a star’s ‘birth cloud’ can cause some stars to accumulate mass without acquiring significant rotation. more

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