Related papers: Cyclo-Synchrotron Emission and Comptonization in O…
We present a complete solution to the cyclotron-synchrotron radiation due to an isotropic distribution of electrons moving in a magnetic field. We make no approximations in the calculations other than artificially broadening the harmonics…
The high energy continuum in Seyfert galaxies and galactic black hole candidates is likely to be produced by a thermal plasma. There are difficulties in understanding what can keep the plasma thermal, especially during fast variations of…
We investigate thermal synchrotron radiation at semi-relativistic and relativistic temperatures. We find an analytic expression for the angle-averaged emission coefficient, and show that it is significantly more accurate that those derived…
We present detailed calculations of the electron thermalization by synchrotron self-absorption accounting for cooling by Compton scattering. For the first time, we solve coupled kinetic equations for electrons and photons without any…
If there was a weak magnetic field in the early universe, cyclotron emission could play an important role in the thermalization of the CMB. We study this process in the tightly coupled primordial electron-photon plasma and find that if the…
We study $e^{\pm}$ pair plasmas in pair equilibrium, which emit high energy radiation by thermal Comptonization of soft photons. We find that the maximum luminosity to size ratio of the source (i.e. the compactness) depends not only on the…
We have developed an improved model of X-ray emission from optically thin, two-temperature accretion flows, \texttt{kerrflow}, using an exact Monte Carlo treatment of global Comptonization as well as with a fully general relativistic…
There are difficulties in understanding what keeps the plasma thermalized in compact sources, especially during rapid variations of the emitted flux. Particle-particle collisions are too inefficient in hot rarefied plasmas, and a faster…
We discuss the role of thermal cyclo-synchrotron emission in a magnetically dominated corona above an accretion disk in an active galaxy or a galactic black hole candidate. The dissipation occurs in localized active regions around the…
We provide simple and accurate analytic approximations for the low frequency double Compton emission coefficient that are applicable in a broad range of physical situations up to mildly relativistic temperatures. These approximations may be…
Electron-positron pair production by collision of photons is investigated in view of application to pulsar physics. We compute the absorption rate of individual gamma-ray photons by an arbitrary anisotropic distribution of softer photons,…
Considering the propagation of off-shell particles in the framework of thermal field theory, we present the general formalism for the calculation of the production rate of soft photons and dileptons from a hot plasma. This approach is…
We present a systematic fit of a model of resonant cyclotron scattering (RCS) to the X and soft gamma-ray data of four magnetars, including anomalous X-ray pulsars, and soft gamma repeaters. In this scenario, non-thermal magnetar spectra in…
Strong soft X-ray emission called soft X-ray excess is often observed in luminous active galactic nuclei (AGN). It has been suggested that the soft X-rays are emitted from a warm ($T=10^6\sim10^7\ \rm{K}$) region that is optically thick for…
We propose a new approximation for the cyclo-synchrotron emissivity of a single electron. In the second part of this work, we discuss a simple application for our approximation, and investigate the heating of electrons through the…
We have obtained new solutions and methods for the process of thermal Comptonization. We modify the solution to the kinetic equation of Sunyaev \& Titarchuk to allow its application up to mildly relativistic electron temperatures and…
Synchrotron emission of relativistic particles in magnetic fields is a process of paramount importance in astrophysics. Although known for over thirty years, there are still aspects of this radiative process that have received little…
We compute the hard X-ray spectra from a hot plasma pervaded by small cold dense clouds. The main cooling mechanism of the plasma is Compton cooling by the soft thermal emission from the clouds. We compute numerically the equilibrium…
We show that Compton scattering of soft photons with energies near 100 eV in thermally stratified black-hole accretion plasmas with temperatures in the range 100 keV - 1 MeV can give rise to an X-ray spectral hardening near 10 keV. This…
Synchrotron radiation and Compton scattering are widely accepted as the most likely emission mechanisms of some astrophysical phenomena, such as gamma-ray bursts (GRBs) and active galactic nuclei (AGNs). The measurement on polarization of…