Radiative corrections to the neutron star mass inferred from QPO frequencies

TL;DR

This paper discusses how radiative corrections influence the interpretation of kHz QPO frequencies and the inferred neutron star mass, potentially explaining observed phenomena like parallel tracks.

Contribution

It introduces radiative corrections into models of QPO frequencies, refining neutron star mass estimates and explaining certain observational features.

Findings

Radiative forces affect QPO frequency interpretations.

Inclusion of radiative corrections alters neutron star mass estimates.

Radiative effects may explain the parallel tracks phenomenon.

Abstract

The frequencies of kHz QPOs are widely interpreted as being indicative of the values of characteristic frequencies related to orbital motion around neutron stars, e.g., the radial epicyclic frequency. In regions directly exposed to the radiation from the luminous neutron star these frequencies change with the luminosity. Including radiative corrections will change the neutron star mass value inferred from the QPO frequencies. Radiative forces may also be behind the puzzling phenomenon of parallel tracks.