We consider the radiative transfer problem in a plane-parallel slab of thermal electrons in the presence of an overcritical magnetic field. Under such conditions, the magnetic field behaves as a birefringent medium for the propagating photons, and the electromagnetic radiation is split into two polarization modes, ordinary and extraordinary, having different cross-sections. When the optical depth of the slab is large, the ordinary-mode photons are strongly Comptonized and the photon field is dominated by an isotropic component. The radiative transfer problem in strong magnetic fields presents many mathematical issues and analytical or numerical solutions can be obtained only under some given approximations. We investigate this problem both from the analytical and numerical point of view, providing a test of the previous analytical estimates and extending these results introducing numerical techniques. We consider the case of low temperature blackbody photons propagating in a sub-relativistic temperature plasma, which allows us to deal with a semi Fokker-Planck approximation of the radiative transfer equation. We report the numerical solution obtained for eigenvalues and eigenfunctions of the space operator, and the emerging Comptonization spectrum of the ordinary-mode photons for any eigenvalue of the space equation and for energies significantly less than the cyclotron energy, which is of the order of MeV for the intensity of the magnetic field here considered. We derived the specific intensity of the ordinary photons, under the approximation of large angle and large optical depth. These assumptions allow the equation to be treated using a diffusion-like approximation.
Energy flow and radiation efficiency in radiative GRMHD simulations of neutron star ultraluminous X-ray sources
Nicolaus Copernicus Astronomical Center of the Polish Academy of Sciences（波兰科学院尼古拉·哥白尼天体物理中心）；Research Centre for Computational Physics and Data Processing, Institute of Physics, Silesian University in Opava（奥帕瓦西里西亚大学物理学院计算物理与数据处理研究中心）；Nicolaus Copernicus Superior School, College of Astronomy and Natural Sciences（尼古拉·哥白尼高等学院天文与自然科学学院）
SN2023ixf: Radiative-transfer modeling of the photospheric phase evolution from the ultraviolet to the infrared
Institut d’Astrophysique de Paris, CNRS-Sorbonne Université（巴黎天体物理学研究所，法国国家科学研究中心-索邦大学）；French-Chilean Laboratory for Astronomy, IRL 3386, CNRS and Instituto de Astrofísica, Pontificia Universidad Católica de Chile（中法天文实验室，法国国家科学研究中心与智利天主教庞蒂菲亚大学天体物理研究所）；Cahill Center for Astrophysics, California Institute of Technology（加州理工学院卡希尔天体物理学中心）；Steward Observatory, University of Arizona（亚利桑那大学斯图尔德天文台）；Department of Astronomy, University of California, Berkeley（加州大学伯克利分校天文学系）；Department of Physics and Astronomy, University of California, Davis（加州大学戴维斯分校物理与天文学系）
