Browsing by Author "Krause, Martin G. H."

Now showing items 1-20 of 27

    • 26Al gamma rays from the Galaxy with INTEGRAL/SPI 

      Pleintinger, Moritz M. M.; Diehl, Roland; Siegert, Thomas; Greiner, Jochen; Krause, Martin G. H. (2023-03-30)
      Context. The presence of radioactive 26Al at 1.8 MeV reveals an ongoing process of nucleosynthesis in the Milky Way. Diffuse emission from its decay can be measured with gamma-ray telescopes in space. The intensity, line ...

    • Can massive stars form in low mass clouds? 

      Smith, Jamie D.; Jaffa, Sarah E.; Krause, Martin G. H. (2023-09-07)
      The conditions required for massive star formation are debated, particularly whether massive stars must form in conjunction with massive clusters. Some authors have advanced the view that stars of any mass (below the total ...

    • Can the Local Bubble explain the radio background? 

      Krause, Martin G. H.; Hardcastle, Martin J. (2021-04-01)
      The ARCADE 2 balloon bolometer along with a number of other instruments have detected what appears to be a radio synchrotron background at frequencies below about 3 GHz. Neither extragalactic radio sources nor diffuse ...

    • Comparing simulated $^{26}$Al maps to gamma-ray measurements 

      Pleintinger, Moritz M. M.; Siegert, Thomas; Diehl, Roland; Fujimoto, Yusuke; Greiner, Jochen; Krause, Martin G. H.; Krumholz, Mark R. (2019-12-03)
      Context. The diffuse gamma-ray emission of $^{26}{\rm Al}$ at 1.8 MeV reflects ongoing nucleosynthesis in the Milky Way, and traces massive-star feedback in the interstellar medium due to its 1 Myr radioactive lifetime. ...

    • Constraints on positron annihilation kinematics in the inner Galaxy 

      Siegert, Thomas; Crocker, Roland M.; Diehl, Roland; Krause, Martin G. H.; Panther, Fiona H.; Pleintinger, Moritz M. M.; Weinberger, Christoph (2019-07-01)
      Context. The annihilation of cosmic positrons with electrons in the interstellar medium results in the strongest persistent γ-ray line signal in the sky. For the past 50 yr, this 511 keV emission - predominantly from the ...

    • CosmoDRAGoN simulations -- I. Dynamics and observable signatures of radio jets in cosmological environments 

      Yates-Jones, Patrick M.; Shabala, Stanislav S.; Power, Chris; Krause, Martin G. H.; Hardcastle, Martin J.; Velastín, Elena A. N. Mohd Noh; Stewart, Georgia S. C. (2023-04-12)
      We present the Cosmological Double Radio Active Galactic Nuclei (CosmoDRAGoN) project: a large suite of simulated AGN jets in cosmological environments. These environments sample the intra-cluster media of galaxy clusters ...

    • Could kilomasers pinpoint supermassive stars? 

      Nowak, Katarzyna; Krause, Martin G. H.; Schaerer, Daniel (2022-09-11)
      A strong nuclear kilomaser, W1, has been found in the nearby galaxy NGC 253, associated with a forming super star cluster. Kilomasers could arise from the accretion disc around supermassive stars (>10^3 Msun), hypothetical ...

    • Dynamics of relativistic radio jets in asymmetric environments 

      Yates-Jones, Patrick M.; Shabala, Stanislav S.; Krause, Martin G. H. (2021-12-01)
      We have carried out relativistic three-dimensional simulations of high-power radio sources propagating into asymmetric cluster environments. We offset the environment by 0 or 1 core radii (equal to 144 kpc), and incline ...

    • eROSITA studies of the Carina Nebula 

      Sasaki, Manami; Robrade, Jan; Krause, Martin G. H.; Knies, Jonathan R.; Tsuge, Kisetsu; Pühlhofer, Gerd; Strong, Andrew (2024-02-23)
      Context. During the first four all-sky surveys eRASS:4, which was carried out from December 2019 to 2021, the extended Roentgen Survey with an Imaging Telescope Array (eROSITA) on board the Spektrum-Roentgen-Gamma (Spektr-RG, ...

    • Galactic 26Al traces metal loss through hot chimneys 

      Krause, Martin G. H.; Rodgers-Lee, Donna; Dale, James E.; Diehl, Roland; Kobayashi, Chiaki (2021-02-01)
      Radioactive 26Al is an excellent tracer for metal ejection in the Milky Way, and can provide a direct constraint on the modelling of supernova feedback in galaxy evolution. Gamma-ray observations of the 26Al decay line ...

    • Galactic Population Synthesis of Radioactive Nucleosynthesis Ejecta 

      Siegert, Thomas; Pleintinger, Moritz M. M.; Diehl, Roland; Krause, Martin G. H.; Greiner, Jochen; Weinberger, Christoph (2023-03-30)
      Diffuse gamma-ray line emission traces freshly produced radioisotopes in the interstellar gas, providing a unique perspective on the entire Galactic cycle of matter from nucleosynthesis in massive stars to their ejection ...

    • How frequent are close supermassive binary black holes in powerful jet sources? 

      Krause, Martin G. H.; Shabala, Stanislav S.; Hardcastle, Martin J.; Böhringer, Hans; Chon, Gayoung; Nawaz, Mohammad A.; Sarzi, Marc; Wagner, Alexander Y. (2019-01-01)
      Supermassive black hole binariesmay be detectable by an upcoming suite of gravitationalwave experiments. Their binary nature can also be revealed by radio jets via a short-period precession driven by the orbital motion as ...

    • An INTEGRAL/SPI view of reticulum II: Particle dark matter and primordial black holes limits in the MeV range 

      Siegert, Thomas; Boehm, Celine; Calore, Francesca; Diehl, Roland; Krause, Martin G. H.; Serpico, Pasquale D.; Vincent, Aaron C. (2022-03-01)
      Reticulum II (Ret II) is a satellite galaxy of the Milky Way and presents a prime target to investigate the nature of dark matter (DM) because of its high mass-to-light ratio. We evaluate a dedicated INTEGRAL observation ...

    • A Markov Chain Monte Carlo approach for measurement of jet precession in radio-loud active galactic nuclei 

      Horton, Maya; Hardcastle, Martin J.; Read, Shaun C.; Krause, Martin G. H. (2020-04-03)
      Jet precession can reveal the presence of binary systems of supermassive black holes. The ability to accurately measure the parameters of jet precession from radio-loud AGN is important for constraining the binary supermassive ...

    • New mechanisms for forming multiple hotspots in radio jets 

      Horton, Maya A.; Krause, Martin G. H.; Hardcastle, Martin J. (2023-03-06)
      Hotspots of radio galaxies are regions of shock-driven particle acceleration. Multiple hotspots have long been identified as potential indicators of jet movement or precession. Two frequent explanations describe a secondary ...

    • Numerical modelling of the lobes of radio galaxies – Paper V: universal pressure profile cluster atmospheres 

      Stimpson, Michael; Hardcastle, Martin J.; Krause, Martin G. H. (2023-09-26)
      We present relativistic magnetohydrodynamic modelling of jets running into hydrostatic, spherically symmetric cluster atmospheres. For the first time in a numerical simulation, we present model cluster atmospheres based ...

    • Physical Processes in Star Formation 

      Girichidis, Philipp; Offner, Stella S. R.; Kritsuk, Alexei G.; Klessen, Ralf S.; Hennebelle, Patrick; Kruijssen, J. M. Diederik; Krause, Martin G. H.; Glover, Simon C. O.; Padovani, Marco (2020-06-02)
      Star formation is a complex multi-scale phenomenon that is of significant importance for astrophysics in general. Stars and star formation are key pillars in observational astronomy from local star forming regions in the ...

    • The Physics of Star Cluster Formation and Evolution 

      Krause, Martin G. H.; Offner, Stella S. R.; Charbonnel, Corinne; Gieles, Mark; Klessen, Ralf S.; Vazquez-Semadeni, Enrique; Ballesteros-Paredes, Javier; Girichidis, Philipp; Kruijssen, J. M. Diederik; Ward, Jacob L.; Zinnecker, Hans (2020-06-02)
      Star clusters form in dense, hierarchically collapsing gas clouds. Bulk kinetic energy is transformed to turbulence with stars forming from cores fed by filaments. In the most compact regions, stellar feedback is least ...

    • PRAiSE: resolved spectral evolution in simulated radio sources 

      Yates-Jones, Patrick M.; Turner, Ross J.; Shabala, Stanislav S.; Krause, Martin G. H. (2022-04-30)
      We present a method for applying spatially resolved adiabatic and radiative loss processes to synthetic radio emission from hydrodynamic simulations of radio sources from active galactic nuclei (AGN). Lagrangian tracer ...

    • Probing gaseous halos of galaxies with radio jets 

      Krause, Martin G. H.; Hardcastle, Martin J.; Shabala, Stanislav S. (2019-07-09)
      Context. Gaseous halos play a key role in understanding inflow, feedback, and the overall baryon budget in galaxies. Literature models predict transitions of the state of the gaseous halo between cold and hot accretion, ...