Irradiation Effects in Compact Binaries

Abstract

Abstract. Irradiation of the secondaries in close binary systems affects their appearance and can drastically change their internal structure and hence long-term evolution. In this paper we review the main effects of external irradiation in close binaries with compact primaries, such as the distortion of the shape of the secondary and the conditions for the occurrence of outer critical configurations, and apply these to normal Xray binaries, including systems such as HZ Her/Her X-l, Vela X-l and black-hole binaries during outburst (e.g. NovaSco). Particular emphasis will be given to the role of circulation driven by the external heating and the radiative surface stress. We have developed a three-dimensional fluid dynamics code for modelling these effects. We present initial results of self-consistent calculations for the circulation in irradiated systems and show how the inclusion of these effects is vital to the understanding and interpretation of any system where external irradiation of the secondary is significant.

Testing modified gravity and no-hair relations for the Kerr-Newman metric through quasiperiodic oscillations of galactic microquasars

“…by Beer and Podsiadlowski [64] who found M = 5.4 ± 0.3M ⊙ from Kepler's Third Law, avoid this problem while remaining consistent with Motta et al [59]. Our aim is to demonstrate that, even with tight error bars on the mass, as achieved by [59], a large range of spins can accommodate QPO observations, a conclusion which is unaltered (but is less evident) if one uses the self-consistent values of the mass from Beer and Podsiadlowski [64]. As better data become available in the future, it would ultimately be worth re-calculating the measured mass based on the assumption of a central Kerr-Newman object following the rigorous statistical approach of Motta et al [59] for an entirely self-consistent analysis, but this lies outside the scope of the present paper.…”

“…Independent optical measurements of the mass of GRO J1665-40, e.g. by Beer and Podsiadlowski [64] who found M = 5.4 ± 0.3M ⊙ from Kepler's Third Law, avoid this problem while remaining consistent with Motta et al [59]. Our aim is to demonstrate that, even with tight error bars on the mass, as achieved by [59], a large range of spins can accommodate QPO observations, a conclusion which is unaltered (but is less evident) if one uses the self-consistent values of the mass from Beer and Podsiadlowski [64].…”