PREPRINT
9F0E2533-75F3-4E2E-8ABD-217858AB7953

Polarized Radiation Signals from Highly Magnetized Neutron Star Surfaces

Kun Hu, Matthew G. Baring, Joseph A. Barchas, George Younes
arXiv:2207.05145

Submitted on 11 July 2022

Abstract

The surfaces of neutron stars are likely sources of strongly polarized soft X rays due to the presence of strong magnetic fields. Scattering transport in the surface layers is critical to the determination of the emergent anisotropy of light intensity, and is strongly influenced by the complicated interplay between linear and circular polarization information. We have developed a magnetic Thomson scattering simulation to model the outer layers of fully-ionized atmospheres in such compact objects. Here we summarize emergent intensities and polarizations from extended atmospheric simulations, spanning considerable ranges of magnetic colatitudes. General relativistic propagation of light from the surface to infinity is fully included. The net polarization degrees are moderate and not very small when summing over a variety of field directions. These results provide an important foundation for observations of magnetars to be acquired by NASA's new IXPE X-ray polarimeter and future X-ray polarimetry missions.

Preprint

Comment: 4 pages, 3 figures, accepted for publication in the proceedings of the IAU Symposium 363, Neutron Star Astrophysics at the Crossroads: Magnetars and the Multimessenger Revolution, eds. E. Troja & M. G. Baring

Subject: Astrophysics - High Energy Astrophysical Phenomena

URL: https://arxiv.org/abs/2207.05145