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Browsing by Author "Krause, Martin"
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26Al kinematics: superbubbles following the spiral arms? : Constraints from the statistics of star clusters and HI supershells
Krause, Martin; Diehl, R.; Bagetakos, Y.; Brinks, E.; Burkert, A.; Gerhard, O.; Greiner, J.; Kretschmer, K.; Siegert, T. (2015-06-12)High energy resolution spectroscopy of the 1.8 MeV radioactive decay line of 26Al with the SPI instrument on board the INTEGRAL satellite has recently revealed that diffuse 26Al has large velocities in comparison to other ... -
3D Hydrodynamic Simulations of Large-Scale Precessing Jets : Radio Morphology
Horton, Maya; Krause, Martin; Hardcastle, Martin (2020-12-04)The prospect of relativistic jets exhibiting complex morphologies as a consequence of geodetic precession has long been hypothesised. We have carried out a 3D hydrodynamics simulation study varying the precession cone ... -
Are Odd Radio Circles phoenixes of powerful radio galaxies?
Shabala, Stanislav; Yates-Jones, Patrick; Jerrim, Larissa; Turner, Ross; Krause, Martin; Norris, Ray; Koribalski, Baerbel; Filipovic, Miroslav; Rudnick, Larry; Power, Chris; Crocker, Roland (2024-03-05)Odd Radio Circles (ORCs) are a class of low surface brightness, circular objects approximately one arcminute in diameter. ORCs were recently discovered in the Australian Square Kilometre Array Pathfinder (ASKAP) data, and ... -
Chaotic star formation: error bars for the star formation efficiency and column density PDF
Jaffa, Sarah; Dale, James; Krause, Martin; Clarke, S. D. (2022-02-09)Simulations are very useful for testing our theoretical understanding of star formation by varying the initial conditions or treatment of various physical mechanisms. However, large, well resolved simulations including ... -
Characterising superclusters with the galaxy cluster distribution
Chon, G.; Böhringer, H.; Collins, C.~A.; Krause, Martin (2014-08-05)Superclusters are the largest observed matter density structures in the Universe. Recently, we presented the first supercluster catalogue constructed with a well-defined selection function based on the X-ray flux-limited ... -
Concurrent formation of supermassive stars and globular clusters : implications for early self-enrichment
Gieles, Mark; Charbonnel, Corinne; Krause, Martin; Henault-Brunet, Vincent; Agertz, Oscar; Lamers, Henny; Bastian, Nathan; Gualandris, Alessia; Zocchi, Alice; Petts, James (2018-08-01)We present a model for the concurrent formation of globular clusters (GCs) and supermassive stars (SMSs, ≳10 3M ⊙) to address the origin of the HeCNONaMgAl abundance anomalies in GCs. GCs form in converging gas flows and ... -
Discovery of an X-ray cavity near the radio lobes of Cygnus A indicating previous AGN activity
Chon, G.; Böhringer, H.; Krause, Martin; Trümper, J. (2012-09-01)Cygnus A harbours the nearest powerful radio jet of a Fanaroff-Riley (FR) class II radio galaxy in a galaxy cluster where the interaction of the jet with the intracluster medium (ICM) can be studied in detail. We use a ... -
The duty cycle of radio galaxies revealed by LOFAR : remnant and restarted radio source populations in the Lockman Hole
Shabala, Stanislav; Jurlin, Nika; Morganti, Raffaella; Brienza, Marisa; Hardcastle, Martin; Godfrey, Leith; Krause, Martin; Turner, Ross (2020-08)Feedback from radio jets associated with Active Galactic Nuclei (AGN) plays a profound role in the evolution of galaxies. Kinetic power of these radio jets appears to show temporal variation, but the mechanism(s) responsible ... -
Gamma-ray spectroscopy of galactic nucleosynthesis
Diehl, Roland; Greiner, Jochen; Krause, Martin; Pleintinger, Moritz; Siegert, Thomas (2023-03-22)Diffuse gamma-ray emission from the decay of radioactive $^{26}$Al is a messenger from the nucleosynthesis activity in our current-day galaxy. Because this material is attributed to ejections from massive stars and their ... -
Gas dynamics of the central few parsec region of NGC 1068 fuelled by the evolving nuclear star cluster
Schartmann, M.; Burkert, A.; Krause, Martin; Camenzind, M.; Meisenheimer, K.; Davies, R.~I. (2010-04-21)Recently, high-resolution observations with the help of the near-infrared adaptive optics integral field spectrograph Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) at the Very Large Telescope ... -
Jet Feedback in Star-Forming Galaxies
Krause, Martin (2023-02-12)In this paper, I review our understanding of how jet feedback works in star-forming galaxies. There are some interesting differences to radiative feedback from Active Galactic Nuclei (AGN). Jets act on galaxy haloes as ... -
Jet interactions with a giant molecular cloud in the Galactic centre and ejection of hypervelocity stars
Silk, J.; Antonuccio-Delogu, V.; Dubois, Y.; Gaibler, V.; Haas, M.~R.; Khochfar, S.; Krause, Martin (2012-09-21)The hypervelocity OB stars in the Milky Way Galaxy were ejected from the central regions some 10-100 million years ago. We argue that these stars, as well as many more abundant bound OB stars in the innermost few parsecs, ... -
Kinematics of massive star ejecta in the Milky Way as traced by $^26$Al
Kretschmer, K.; Diehl, R.; Krause, Martin; Burkert, A.; Fierlinger, K.; Gerhard, O.; Greiner, J.; Wang, W. (2013-11-19)Context. Massive stars form in groups and their winds and supernova explosions create superbubbles up to kpc in size. The fate of their ejecta is of vital importance for the dynamics of the interstellar medium, for chemical ... -
Magnetohydrodynamic stability of broad line region clouds
Krause, Martin; Schartmann, M.; Burkert, A. (2012-10-01)Hydrodynamic stability has been a longstanding issue for the cloud model of the broad line region in active galactic nuclei. We argue that the clouds may be gravitationally bound to the supermassive black hole. If true, ... -
The non-thermal superbubble in IC 10 : the generation of cosmic ray electrons caught in the act
Heesen, V.; Brinks, E.; Krause, Martin; Harwood, J.J.; Rau, U.; Rupen, M. P.; Hunter, D. A.; Chyzy, K.T.; Kitchener, Ben (2015-02-01)Superbubbles are crucial for stellar feedback, with supposedly high (of the order of 10 per cent) thermalization rates. We combined multiband radio continuum observations from the Very Large Array (VLA) with Effelsberg ... -
Numerical modelling of the lobes of radio galaxies in cluster environments
Hardcastle, M.J.; Krause, Martin (2013-03-21)We have carried out two-dimensional, axisymmetric, hydrodynamic numerical modelling of the evolution of radio galaxy lobes. The emphasis of our work is on including realistic hot-gas environments in the simulations and on ... -
Numerical modelling of the lobes of radio galaxies in cluster environments II : Magnetic field configuration and observability
Hardcastle, M.J.; Krause, Martin (2014-09-11)We describe three-dimensional magnetohydrodynamical modelling of powerful radio galaxies in realistic poor cluster environments. This modelling extends our earlier work on the hydrodynamics of radio galaxies as a function ... -
Numerical modelling of the lobes of radio galaxies in cluster environments – III. Powerful relativistic and non-relativistic jets
English, William; Hardcastle, Martin; Krause, Martin (2016-09-11)We present results from two suites of simulations of powerful radio galaxies in poor cluster environments, with a focus on the formation and evolution of the radio lobes. One suite of models uses relativistic hydrodynamics ... -
Observability of intermittent radio sources in galaxy groups and clusters
Yates, Patrick; Shabala, Stanislav; Krause, Martin (2018-11-11)We have carried out numerical hydrodynamic simulations of radio jets from active galactic nuclei using the PLUTO simulation code, with the aim of investigating the effect of different environments and intermittency of ... -
Radiation feedback on dusty clouds during Seyfert activity
Schartmann, M.; Krause, Martin; Burkert, A. (2011-07-21)We investigate the evolution of dusty gas clouds falling into the centre of an active Seyfert nucleus. 2D high-resolution radiation hydrodynamics simulations are performed to study the fate of single clouds and the interaction ...