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Browsing by Author "Krause, M."
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3D magnetohydrodynamic simulations of the evolution of magnetic fields in Fanaroff-Riley class II radio sources
Huarte-Espinosa, M.; Krause, M.; Alexander, P. (2011-10-11)Radio observations of Fanaroff–Riley class II (FR II) sources often show correlations between the synchrotron emission and the linear-polarimetric distributions. Magnetic position vectors seem to align with the projected ... -
3D-MHD simulations of the evolution of magnetic fields in FR II radio sources
Huarte-Espinosa, M.; Krause, M.; Alexander, P. (2010-09-01)3D-MHD numerical simulations of bipolar, hypersonic, weakly magnetized jets and synthetic synchrotron observations are presented to study the structure and evolution of magnetic fields in FR II radio sources. The magnetic ... -
Absorbers and Globular Cluster Formation in Powerful High Redshift Radio Galaxies
Krause, M. (2002-04-01)A radiative hydrodynamic simulation for a typical, powerful high redshift radio galaxy is presented. The jet is injected at one third the speed of light into a 10 000 times denser, homogeneous medium. In the beginning of ... -
Are there any first-generation stars in globular clusters today?
Charbonnel, C.; Chantereau, W.; Krause, M.; Primas, F.; Wang, Y. (2014-09-22)Context. Several models compete to explain the abundance properties of stellar populations in globular clusters. One of the main constraints is the present-day ratio of first- and second-generation stars that are currently ... -
Asymmetries in extragalactic double radio sources: clues from 3D simulations of jet-disc interaction
Gaibler, V.; Khochfar, S.; Krause, M. (2011-02-11)Observational and theoretical studies of extragalactic radio sources have suggested that an inhomogeneous environment may be responsible for observed arm-length asymmetries of jets and the properties of extended emission-line ... -
Chemical enrichment of the intracluster medium by FR II radio sources
Heath, D.; Krause, M.; Alexander, P. (2007-01-21)We present 2D axisymmetric hydrodynamic simulations investigating the long-term effect of Fanaroff-Riley type II radio galaxies on the metal distribution of the surrounding intracluster medium (ICM). A light jet is injected ... -
Cosmic rays and the magnetic field in the nearby starburst galaxy NGC 253 III.Helical magnetic fields in the nuclear outflow
Heesen, V.; Beck, R.; Krause, M.; Dettmar, R.-J. (2011-01-01)Context.Magnetic fields are good tracers of gas compression by shock waves in the interstellar medium. These can be caused by the interaction of star-formation driven outflows from individual star formation sites as described ... -
Cosmic rays and the magnetic field in the nearby starburst galaxy NGC 253. II The magnetic field
Heesen, V.; Krause, M.; Beck, R.; Dettmar, R-J. (2009)Context. There are several edge-on galaxies with a known magnetic field structure in their halo. A vertical magnetic field significantly enhances the cosmic-ray transport from the disk into the halo. This could explain the ... -
Did globular clusters contribute to the stellar population of the Galactic halo?
Charbonnel, C.; Krause, M. (2016-05-09)The origin of Galactic halo stars and the contribution of globular clusters (GC) to this stellar population have long been (and still are) debated. The discovery of multiple stellar populations with peculiar chemical ... -
Early 56Ni decay gamma rays from SN2014J suggest an unusual explosion
Diehl, R.; Siegert, T.; Hillebrandt, W.; Grebenev, S.~A.; Greiner, J.; Krause, M.; Kromer, M.; Maeda, K.; Röpke, F.; Taubenberger, S. (2014-09-05)Type Ia supernovae result from binary systems that include a carbon-oxygen white dwarf, and these thermonuclear explosions typically produce 0.5 solar mass of radioactive 56Ni. The 56Ni is commonly believed to be buried ... -
Evolution of the ISM and Galactic Activity
Gaibler, V.; Camenzind, M.; Krause, M. (2005-02-01)We study the effects of time-dependent mass injection and heating on the evolution of the interstellar medium (ISM) in elliptical galaxies. As the large and luminous ellipticals have supermassive black holes at their cores, ... -
Extragalactic Radio Sources as a Piece of the Cosmological Jigsaw
Krause, M. (2018-02-26)Early on, extragalactic radio sources have pointed to a cosmologically evolv- ing Universe. They were also an important piece of evidence for the existence of supermassive black holes, now thought to be a key component of ... -
Feedback by massive stars and the emergence of superbubbles. I. Energy efficiency and Vishniac instabilities
Krause, M.; Fierlinger, K.; Diehl, R.; Burkert, A.; Voss, R.; Ziegler, U. (2013-01-24)Context. Massive stars influence their environment through stellar winds, ionising radiation, and supernova explosions. This is signified by observed interstellar bubbles. Such feedback is an important factor for galaxy ... -
Feedback by massive stars and the emergence of superbubbles. II. X-ray properties
Krause, M.; Diehl, R.; Böhringer, H.; Freyberg, M.; Lubos, D. (2014-06-20)Context. In a previous paper we investigated the energy transfer of massive stars to the interstellar medium (ISM) as a function of time and the geometrical configuration of three massive stars via 3D-mesh-refining ... -
Galactic wind shells and high redshift radio galaxies. On the nature of associated absorbers
Krause, M. (2005-06-03)A jet is simulated on the background of a galactic wind headed by a radiative bow shock. The wind shell, which is due to the radiative bow shock, is effectively destroyed by the impact of the jet cocoon, thanks to ... -
Gamma-Ray Emission of 60Fe and 26Al Radioactivity in Our Galaxy
Wang, W.; Siegert, Thomas; Dai, Z. G.; Diehl, R.; Greiner, J.; Heger, A.; Krause, M.; Lang, M.; Pleintinger, M. M. M.; Zhang, X. L. (2020-02-04)The isotopes 60Fe and 26Al originate from massive stars and their supernovae, reflecting ongoing nucleosynthesis in the Galaxy. We studied the gamma-ray emission from these isotopes at characteristic energies 1173, 1332, ... -
INTEGRAL/SPI γ -ray line spectroscopy : Response and background characteristics
Diehl, R.; Siegert, T.; Greiner, J.; Krause, M.; Kretschmer, K.; Lang, M.; Pleintinger, M.; Strong, A.~W.; Weinberger, C.; Zhang, X. (2018-03-20)Context. The space based γ-ray observatory INTEGRAL of the European Space Agency (ESA) includes the spectrometer instrument "SPI". This is a coded mask telescope featuring a 19-element Germanium detector array for ... -
Interaction of Fanaroff-Riley class II radio jets with a randomly magnetized intracluster medium
Huarte-Espinosa, M.; Krause, M.; Alexander, P. (2011-12-11)A combination of 3D magnetohydrodynamics and synthetic numerical simulations are presented to follow the evolution of a randomly magnetized plasma that models the intracluster medium, under the isolated effects of powerful, ... -
Jet-induced star formation in gas-rich galaxies
Gaibler, V.; Khochfar, S.; Krause, M.; Silk, J. (2012-09-01)Feedback from active galactic nuclei (AGN) has become a major component in simulations of galaxy evolution, in particular for massive galaxies. AGN jets have been shown to provide a large amount of energy and are capable ... -
Measurements of the cosmological evolution of magnetic fields with the Square Kilometre Array
Krause, M.; Alexander, P.; Bolton, R.; Geisbüsch, J.; Green, D.~A.; Riley, J. (2009-12-01)We investigate the potential of the Square Kilometre Array (SKA) for measuring the magnetic fields in clusters of galaxies via Faraday rotation of background polarized sources. The populations of clusters and radio sources ...