  The propagation of ion-acoustic solitary waves (IASWs) in a magnetized,
collisionless degenerate plasma system for describing collective plasma
oscillations in dense quantum plasmas with relativistically degenerate
electrons, oppositely charged inertial ions, and positively charged immobile
heavy elements is investigated theoretically. The perturbations of the
magnetized quantum plasma are studied employing the reductive perturbation
technique to derive the Korteweg-de Vries (K-dV) and the modified K-dV (mK-dV)
equations that admits solitary wave solutions. Chandrasekhar limits are used to
investigate the degeneracy effects of interstellar compact objects through
equation of state for degenerate electrons in case of non-relativistic and
ultra-relativistic cases. The basic properties of small but finite-amplitude
IASWs are modified significantly by the combined effects of the degenerate
electron number density, pair ion number density, static heavy element number
density and magnetic field. It is found that the obliqueness affects both the
amplitude and width of the solitary waves, whereas the other parameters mainly
influence the width of the solitons. The results presented in this paper can be
useful for future investigations of astrophysical multi-ion plasmas.
