Stellar wind and stellar disc models of dispersion and rotation measure variations in the PSR B1259 – 63/SS2883 binary system

Abstract

Two models of the PSR B1259 – 63/SS2883 binary system are evaluated to determine whether they account for the orbital variations in dispersion measure (DM) and rotation measure (RM) observed during the 1994 periastron passage of PSR B1259 – 63. In the first model, the DM and RM variations are produced by an ionized, radiatively driven, coronal wind from SS2883. The electron density ne and magnetic field B vary as power laws with distance r from SS2883, and the wind terminates where it collides with the relativistic, electron-positron wind from PSR B1259 – 63. It is shown that this model - popular in the literature -cannot reproduce the observed pre-periastron rise in DM unless one has $n..