X-Ray Spectra of Z Sources

A physically consistent model has been proposed that seeks to explain in a unified way the X-ray spectra and rapid variability of the Z sources and other weakly magnetic neutron stars in low-mass systems. Here we describe a simple, four-parameter spectral model derived from the unified model that accurately reproduces the X-ray colors, spectra, and count rates of the Z sources. In this model, photons are produced primarily by electron cyclotron emission in the neutron star magnetosphere and are then Comptonized in the magnetosphere, hot central corona, and inward radial flow. In addition to explaining their Z tracks, the model explains several other previously unexplained properties of the Z sources.

[1]  M. Miller,et al.  Critical radiation fluxes and luminosities of black holes and relativistic stars , 1995 .

[2]  Myeong-Gu Park,et al.  Oscillatory Modes in Near-critical Accretion Flows , 1995 .

[3]  Kazuhisa Mitsuda,et al.  Searches for millisecond pulsations on low-mass x-ray binaries , 1994 .

[4]  F. Lamb,et al.  Energy dependence of normal branch quasi-periodic intensity oscillations in low-mass X-ray binaries , 1992 .

[5]  P. Ghosh,et al.  DIAGNOSTICS OF DISK-MAGNETOSPHERE INTERACTION IN NEUTRON STAR BINARIES , 1992 .

[6]  E. V. Heuvel,et al.  X-ray binaries and recycled pulsars. , 1992 .

[7]  F. Lamb,et al.  Origin of 'normal-branch' quasiperiodic oscillations in low-mass X-ray binary systems , 1989, Nature.

[8]  M. Klis.  Quasi-Periodic Oscillations and Noise in Low-Mass X-Ray Binaries , 1989 .

[9]  S. Woosley,et al.  Thermal Cyclotron Reprocessing of Gamma-Ray Bursts: Theory and Model Spectra , 1988 .

[10]  L. Stella,et al.  The X-ray spectral properties of accretion discs in X-ray binaries , 1988 .

[11]  F. Lamb,et al.  Power spectra of quasi-periodic oscillations in luminous X-ray stars , 1987 .

[12]  J. Brainerd,et al.  Effect of an electron scattering cloud on X-ray oscillations produced by beaming , 1987 .

[13]  M. A. Alpar,et al.  Quasi-periodic oscillations in bright galactic-bulge X-ray sources , 1985, Nature.

[14]  J. Shaham,et al.  Is GX5 – 1 a millisecond pulsar? , 1985, Nature.

[15]  W. Lewin,et al.  Galactic and extragalactic compact X-Ray sources , 1985 .

[16]  Dan McCammon,et al.  Interstellar photoelectric absorption cross-sections, 0.03-10 keV , 1983 .

[17]  G. Rybicki,et al.  Radiative processes in astrophysics , 1979 .