2009/12/14 by H. Hanayama, Hidekazu Hanayama, Hanayama, Hidekazu +4
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Astrophysics and Star Formation Studies #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #Solar and Space Plasma Dynamics #astro-ph.CO
paper · pdf · doi:10.48550/arxiv.0912.2686
24 pages, 9 figures, submitted to PASJ
openalex publication_date 2009/12/14 · arxiv created 2010/11/16 · arxiv updated 2010/11/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Origin of the magnetic field ubiquitous in the Universe is studied based on the Biermann mechanism, which is expected to work in the non-barotropic region. We perform a series of two-dimensional MHD simulations of the first generation supernova remnant (SNR) expanding in the inhomogeneous interstellar matter (ISM) and study the Biermann mechanism working in the interior of the SNR. Especially, we pay attention to the relaxation process of electron and ion temperatures via the Coulomb interaction. In the early SNR in which the electron temperature is much lower than the ion temperature, the Biermann mechanism is ineffective, since the gradient of electron pressure is small. Magnetic fields begin to be generated just behind the shock front when the electron temperature is sufficiently relaxed. Assuming the explosion energy of 1052 erg, the total magnetic energy generated reaches about 1026 erg and does not depend strongly on the parameters of either SNR or ISM. Analytic expression to estimate the magnetic total energy is presented and it is shown this agrees well with our numerical results. Finally we evaluate the expected amplitude of magnetic fields in protogalaxies as ~10-19 G, which is sufficient for seed fields of the observed galactic magnetic fields.