1st Abstract
| Title (1st Abstract) | Magnetohydrodynamic simulations of the polarized radio emission of the adiabatic SNRs in ISM with nonuniform distribution of density and magnetic field |
| First Author | Oleh Petruk |
| Affiliation | Astronomical Observatory, Palermo, Italy; IAPMM, Lviv, Ukraine |
| Additional Authors | Rino Bandiera / Arcetri Astrophysical Observatory, Florence, Italy |
| Presentation options | |
| Session | 1. Radiation studies from gamma-rays to radio in Galactic and Extragalactic SNRs |
| 1st Abstract | Polarized radio emission has been mapped with great details in several Galactic supernova remnants (SNRs). The polarization of synchrotron emission contains a wealth of information but has not yet been exploited to the extent it deserves. We have developed a numerical method to model the maps of the Stokes parameters for SNRs during their adiabatic phase of evolution, in either a uniform or a non-uniform environment. The method consists in the following steps. 1. A 3-dimensional magneto-hydrodynamical structure of the SNR is simulated, taking into account the interstellar magnetic field, and a possible gradient of the ISM density and/or of the ambient magnetic field. 2. The acceleration of particles at the forward shock and their evolution downstream are modelled. 3. The generation and dissipation of the turbulent component of magnetic field has been calculated everywhere in the SNR, taking into account its interaction with the accelerated particles. 4. Our generalization of the classical synchrotron theory, to include both the ordered and the disordered components of magnetic field, is used to model the emission. 5. The internal Faraday rotation of the polarization plane is considered. 6. Finally, 2-D maps are derived, for different orientations of the SNR with respect to the observer. We present details of the model, as well as some results of the numerical simulations. |
2nd Abstract
| Title (2nd abstract) | Magnetohydrodynamic simulations of the post-adiabatic supernova remnants in the interstellar magnetic field |
| First Author (2nd abstract) | Oleh Petruk |
| Affiliation (2nd abstract) | Astronomical Observatory, Palermo, Italy; IAPMM, Lviv, Ukraine |
| Additional Authors (2nd abstract) | Taras Kuzyo / Institute for Applied Problems in Mechanics and Mathematics, Lviv, Ukraine |
| Presentation options (2nd abstract) | |
| Session (2nd abstract) | 4. Magnetic fields in SNRs and PWNe |
| 2nd Abstract | The evolution of the adiabatic supernova remnants (SNRs) is typically described by the Sedov analytical solutions for the strong point explosion. The speed and the temperature of the shock wave decreases with time and the adiabatic condition is violated due to increase of the radiative losses of energy. As a result, the SNR shock enters the radiative stage. The duration of the transition phase from the adiabatic to the fully radiative stage is almost the same as the adiabatic stage. The period of time between the end of the adiabatic and the beginning of the radiative stage is called the post-adiabatic stage. Hydrodynamic properties of the post-adiabatic SNRs are well known. In contrast, the effect of the interstellar magnetic field on the evolution of such SNRs is not studied. We have used the code PLUTO (Mignone et al. 2007) in order to solve the system of magneto-hydrodynamic (MHD) equations with the radiative losses numerically. Influence of different values of the magnetic field strengths as well as its different orientation (perpendicular and parallel to the shock normal) on the evolution of SNRs are investigated. We have shown that the parallel magnetic field does not affect the distribution of the hydrodynamic parameters, while the presence of the perpendicular field leads to the significant decrease of the gas compression factor; this effect becomes more prominent for higher magnetic field strengths. The study is important in particular for the cases of the SNR-molecular cloud interaction where one may expect an increase of the hadronic component of the gamma-ray emission. |
Account
| First Name | Oleh |
| Last Name | Petruk |
| Institution | Astronomical Observatory, Palermo |
| Country | Italy |