Statistical features of multiple Compton scattering in a strong magnetic field

Physical review. D/Physical review. D., vol. 105

Abstract

Compton scattering is a key process shaping spectra formation and accretion flow dynamics in accreting strongly magnetized neutron stars. A strong magnetic field affects the scattering cross section and makes it dependent on photon energy, momentum, and polarization state. Using Monte Carlo simulations, we investigate statistical features of Compton scattering of polarized x-ray radiation in a strong magnetic field. Our analysis is focused on photon gas behavior well inside the scattering region. We take into account the resonant scattering at the fundamental cyclotron frequency, thermal distribution of electrons at the ground Landau level, and bulk velocity of the electron gas. We show that (i) the photons scattered around the cyclotron energy by the electron gas at rest tend to acquire the final energy close to the cyclotron one with very small dispersion measure; (ii) the redistribution of photons within the Doppler core of cyclotron resonance differs significantly from the complete redistribution; (iii) the efficiency of momentum transfer from photons to the electron gas is affected by the temperature of electron gas both for photons at cyclotron energy and below it; (iv) the momentum transfer from photons to the electron gas of nonzero bulk velocity is more efficient in the case of magnetic scattering.

Authors 6

1. Alexander A. Mushtukov Aachen Leiden Observatory

   Leiden University · University of Oxford · Leiden Observatory

   Affiliation as printed

   Astrophysics, Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, United Kingdom

   Leiden Observatory, Leiden University, NL-2300RA Leiden, Netherlands

2. Ivan D Markozov

   St Petersburg University

   Affiliation as printed

   Sobolev Astronomical Institute, Saint Petersburg State University, Saint Petersburg 198504, Russia

3. В. Ф. Сулейманов

   University of Tübingen

   Affiliation as printed

   Institut für Astronomie und Astrophysik, Universität Tübingen, Sand 1, D-72076 Tübingen, Germany

4. Dmitrij I. Nagirner

   St Petersburg University

   Affiliation as printed

   Sobolev Astronomical Institute, Saint Petersburg State University, Saint Petersburg 198504, Russia

5. A. D. Kaminker

   Ioffe Institute

   Affiliation as printed

   Ioffe Institute, Politekhnicheskaya 26, Saint Petersburg 194021, Russia

6. Simon Portegies Zwart Aachen Leiden Observatory

   Leiden University · Leiden Observatory

   Affiliation as printed

   Leiden Observatory, Leiden University, NL-2300RA Leiden, Netherlands