Results 101 to 110 of about 221 (127)
Cosmic rays in astrospheres [PDF]
Astronomy and Astrophysics, 2015 Cosmic rays passing through large astrospheres can be efficiently cooled inside these "cavities" in the interstellar medium. Moreover, the energy spectra of these energetic particles are already modulated in front of the astrospherical bow shocks. We study the cosmic ray flux in and around lambda Cephei as an example for an astrosphere. The large-scale
Horst Fichtner +2 more
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Comic ray flux anisotropies caused by astrospheres [PDF]
Astroparticle Physics, 2016 Huge astrospheres or stellar wind bubbles influence the propagation of cosmic rays at energies up to the TeV range and can act as small-scale sinks decreasing the cosmic ray flux. We model such a sink (in 2D) by a sphere of radius 10\,pc embedded within a sphere of a radius of 1\,kpc.
Horst Fichtner +2 more
exaly +5 more sources
Comparison of astrospheres around cool and hot stars [PDF]
Journal of Physics: Conference Series, 2016 Simulations of astrospheres around hot and cool stars have recently move into the focus of scientific research. We describe here the differences between the astrospheres around hot and cool stars. While those around the former are huge (on pc scales) because of their high stellar wind momentum flow, those around cool stars are on a AU scale and the ...
Horst Fichtner, Klaus Scherer
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Magnetic Reconnection at Planetary Bodies and Astrospheres
Space Science Reviews, 2023 AbstractMagnetic reconnection is a fundamental mechanism for the transport of mass and energy in planetary magnetospheres and astrospheres. While the process of reconnection is itself ubiquitous across a multitude of systems, the techniques used for its analysis can vary across scientific disciplines.
Daniel Gershman, Stephen Fuselier
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Shock structures of astrospheres [PDF]
Astronomy and Astrophysics, 2016 The interaction between a supersonic stellar wind and a (super-)sonic interstellar wind has recently been viewed with new interest. We here first give an overview of the modeling, which includes the heliosphere as an example of a special astrosphere.
Horst Fichtner, Klaus Scherer
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MHD-shock structures of astrospheres: λ Cephei -like astrospheres [PDF]
Monthly Notices of the Royal Astronomical Society, 2020 ABSTRACT The interpretation of recent observations of bow shocks around O-stars and the creation of corresponding models require a detailed understanding of the associated (magneto-)hydrodynamic structures. We base our study on 3D numerical (magneto-)hydrodynamical models, which are analysed using the dynamically relevant parameters, in ...
Konstantin Herbst +2 more
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Astronomy and Astrophysics, 2022 Context. State of the art simulations of astrospheres are modelled using three-dimensional (3D) magnetohydrodynamics (MHD). An astrospheric interaction of a stellar wind (SW) with its surrounding interstellar medium (ISM) can only generate a bow shock if
Jens Kleimann +2 more
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X-ray detection of astrospheres around three main-sequence stars and their mass-loss rates [PDF]
Nature AstronomyStellar winds of cool main-sequence stars are difficult to constrain observationally. One way to measure stellar mass-loss rates is to detect the soft X-ray emission from stellar astrospheres produced by charge exchange between heavy ions of the stellar ...
Manuel Guedel +2 more
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Lyman-α observations of astrospheres [PDF]
ASTRA Proceedings, 2014 Abstract. Charge-exchange reactions between outflowing stellar wind protons and interstellar neutral hydrogen atoms entering a stellar astrosphere produce a region of piled-up-decelerated neutral hydrogen called the hydrogen wall. Absorption by this gas, which is observed in stellar Lyman-α emission lines, provides the only viable technique at this ...
Jeffrey Linsky
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