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Przeglądanie wg autora "Hanasz, Michał"

Repozytorium Uniwersytetu Mikołaja Kopernika

Przeglądanie wg autora "Hanasz, Michał"

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  • 3D model of magnetic fields evolution in dwarf irregular galaxies 
    Siejkowski, Hubert; Soida, Marian; Otmianowska-Mazur, Katarzyna; Hanasz, Michał; Bomans, Dominik J. (2011-01-12)
    Radio observations show that magnetic fields are present in dwarf irregular galaxies (dIrr) and its strength is comparable to that found in spiral galaxies. Slow rotation, weak shear and shallow gravitational potential are ...
  • Amplification of Galactic Magnetic Fields by the Cosmic-Ray Driven Dynamo 
    Hanasz, Michał; Kowal, Grzegorz; Otmianowska-Mazur, Katarzyna; Lesch, Harald (2004-02-27)
    We present the first numerical model of the magnetohydrodynamical cosmic-ray (CR) driven dynamo of the type proposed by Parker (1992). The driving force of the amplification process comes from CRs injected into the galactic ...
  • Can the cosmic-ray driven dynamo model explain the observations of the polarized emission of edge-on galaxies? 
    Otmianowska-Mazur, Katarzyna; Soida, Marian; Kulesza-Żydzik, Barbara; Hanasz, Michał; Kowal, Grzegorz (2008-12-11)
    In the present paper we construct maps of polarized synchrotron radio emission of a whole galaxy, based on local models of the cosmic ray (CR) driven dynamo. We perform numerical simulations of the dynamo in local Cartesian ...
  • Comparison between particle and fluid approximations to dust dynamics 
    Drążkowska, Joanna; Hanasz, Michał; Kowalik, Kacper (2010-09-03)
    We present a new particle module of the magnetohydrodynamic (MHD) Piernik code. The original multi-fluid grid code based on the Relaxing Total Variation Diminishing (RTVD) scheme has been extended by addition of dust ...
  • Conditions for fast magnetic reconnection in astrophysical plasmas 
    Hanasz, Michał; Lesch, Harald (2003-03-27)
    We investigate favourable circumstances for fast magnetic reconnection in astrophysical plasmas based on recent results by Rogers et al. (2001). Given that a critical magnetic field structure with antiparallel field lines ...
  • Cosmic-ray driven dynamo in galactic disks 
    Hanasz, Michał; Otmianowska-Mazur, Katarzyna; Lesch, Harald; Kowal, Grzegorz; Soida, Marian; Wóltański, Dominik; Kowalik, Kacper; Pawłaszek, Rafał; Kulesza-Żydzik, Barbara (2008-12-31)
    We present new developments on the Cosmic--Ray driven, galactic dynamo, modeled by means of direct, resistive CR--MHD simulations, performed with ZEUS and PIERNIK codes. The dynamo action, leading to the amplification of ...
  • Cosmic-ray driven dynamo in galaxies 
    Hanasz, Michał; Wóltański, Dominik; Kowalik, Kacper; Kotarba, Hanna (2011-02-07)
    We present recent developments of global galactic-scale numerical models of the Cosmic Ray (CR) driven dynamo, which was originally proposed by Parker (1992). We conduct a series of direct CR+MHD numerical simulations of ...
  • Cosmic-ray driven dynamo in the interstellar medium of irregular galaxies 
    Siejkowski, Hubert; Soida, Marian; Otmianowska-Mazur, Katarzyna; Hanasz, Michał; Bomans, Dominik J. (2010-09-27)
    Irregular galaxies are usually smaller and less massive than their spiral, S0, and elliptical counterparts. Radio observations indicate that a magnetic field is present in irregular galaxies whose value is similar to that ...
  • Cosmic-ray driven dynamo in the medium of irregular galaxy 
    Siejkowski, Hubert; Soida, Marian; Otmianowska-Mazur, Katarzyna; Hanasz, Michał; Bomans, Dominik J. (2009-01-12)
    We investigate the cosmic ray driven dynamo in the interstellar medium of irregular galaxy. The observations (Chyzy et al. 2000, 2003) show that the magnetic field in irregular galaxies is present and its value reaches the ...
  • Cosmic ray driven dynamo in barred and ringed galaxies 
    Kulpa-Dybeł, K.; Otmianowska-Mazur, Katarzyna; Kulesza-Żydzik, Barbara; Kowal, Grzegorz; Wóltański, Dominik; Hanasz, Michał; Kowalik, Kacper (2011-01-02)
    We study the global evolution of the magnetic field and interstellar medium (ISM) of the barred and ringed galaxies in the presence of non-axisymmetric components of the potential, i.e. the bar and/or the oval perturbations. ...
  • Cosmic ray driven dynamo in galactic disks. A parameter study 
    Hanasz, Michał; Otmianowska-Mazur, Katarzyna; Kowal, Grzegorz; Lesch, Harald (2008-12-19)
    We present a parameter study of the magnetohydrodynamical dynamo driven by cosmic rays in the interstellar medium (ISM) focusing on the efficiency of magnetic field amplification and the issue of energy equipartition between ...
  • Discussion of the Electromotive Force Terms in the Model of Parker-unstable Galactic Disks with Cosmic Rays and Shear 
    Otmianowska-Mazur, Katarzyna; Kowal, Grzegorz; Hanasz, Michał (2007-10-17)
    We analyze the electromotive force (EMF) terms and basic assumptions of the linear and nonlinear dynamo theories in our three-dimensional (3D) numerical model of the Parker instability with cosmic rays and shear in a ...
  • Global galactic dynamo driven by cosmic-rays and exploding magnetized stars 
    Hanasz, Michał; Wóltański, Dominik; Kowalik, Kacper (2009-11-05)
    We report first results of first global galactic-scale CR-MHD simulations of cosmic-ray-driven dynamo. We investigate the dynamics of magnetized interstellar medium (ISM), which is dynamically coupled with the cosmic-ray ...
  • Global simulations of galactic dynamo driven by cosmic-rays and exploding magnetized stars 
    Hanasz, Michał; Wóltański, Dominik; Kowalik, Kacper; Pawłaszek, Rafał (2008-12-31)
    We conduct global galactic--scale magnetohydrodynamical (MHD) simulations of the cosmic--ray driven dynamo. We assume that exploding stars deposit small--scale, randomly oriented, dipolar magnetic fields into the differentially ...
  • Global simulations of the magnetic field evolution under the influence of the cosmic-ray-driven dynamo 
    Kulpa-Dybeł, K.; Otmianowska-Mazur, Katarzyna; Kulesza-Żydzik, Barbara; Kowal, Grzegorz; Hanasz, Michał; Wóltański, Dominik; Kowalik, Kacper (2011-06-01)
    We present three-dimensional global numerical simulations of the cosmic-ray (CR) driven dynamo in barred galaxies. We study the evolution of the interstellar medium of the barred galaxy in the presence of non-axisymmetric ...
  • Hydrodynamical instability of extragalactic stratified jets 
    Hanasz, Michał; Sol, Helene (1997-11-20)
    The recent development of tomographic analysis of radio data shows the presence of sheaths around several extragalactic jets. We have studied the Kelvin-Helmholtz instability of such stratified jets, describing them as ...
  • Incorporation of cosmic ray transport into the ZEUS MHD code. Application for studies of Parker instability in the ISM 
    Hanasz, Michał; Lesch, Harald (2003-09-24)
    We present a numerical algorithm for the incorporation of the active cosmic ray transport, into the ZEUS-3D magnetohydrodynamical code. The cosmic ray transport is described by the diffusion-advection equation. The applied ...
  • Influence of internal energy on the stability of relativistic flows 
    Perucho, Manuel; Hanasz, Michał; Marti, Jose-Maria; Sol, Helene (2002-12-05)
    A set of simulations concerning the influence of internal energy on the stability of relativistic jets is presented. Results show that perturbations saturate when the amplitude of the velocity perturbation approaches the ...
  • Initial Magnetization of Galaxies by Exploding, Magnetized Stars 
    Kowalik, Kacper; Hanasz, Michał (2007-12-14)
    We conduct a series of magnetohydrodynamical (MHD) simulations of magnetized interstellar medium (ISM) disturbed by exploding stars. Each star deposits a randomly oriented, dipolar magnetic field into ISM. The simulations ...
  • Kelvin-Helmholtz instability of relativistic jets - the transition from linear to nonlinear regime 
    Hanasz, Michał (1997-11-23)
    The observed wiggles and knots in astrophysical jets as well as the curvilinear motion of radio emitting features are frequently interpreted as signatures of the Kelvin-Helmholtz (KH) instability (eg. Hardee 1987). We ...