Astrophysics of the Soft Gamma Repeaters and Anomalous X-Ray Pulsars

Observations of thermal radiation from neutron stars can potentially provide information about the states of supranuclear matter in the interiors of these stars with the aid of the theory of neutron-star thermal evolution. We review the basics of this theory for isolated neutron stars with strong magnetic fields, including most relevant thermodynamic and kinetic properties in the stellar core, crust, and blanketing envelopes.

show abstract

Atmospheres of magnetized neutron stars: vacuum polarization and partially ionized models

Lai

Potekhin

et al. 2004

Advances in Space Research

View full text Add to dashboard Cite

We construct hydrogen atmosphere models for magnetized neutron stars in radiative equilibrium with surface fields B = 10 12 −5×10 14 G and effective temperatures T eff ∼ a few×10 5 −10 6 K by solving the full radiative transfer equations for both polarization modes in the magnetized hydrogen plasma. The atmospheres directly determine the characteristics of thermal emission from isolated neutron stars. We study the effects of vacuum polarization and bound atoms on the atmosphere structure and spectra. For the lower magnetic field models (B ∼ 10 12 G), the spectral features due to neutral atoms lie at extreme UV and very soft X-ray energies and therefore are not likely to be observed. However, the continuum flux is also different from the fully ionized case, especially at lower energies. For the higher magnetic field models, we find that vacuum polarization softens the high energy tail of the thermal spectrum. We show that this depression of continuum flux strongly suppresses not only the proton cyclotron line but also spectral features due to bound species; therefore spectral lines or features in thermal radiation are more difficult to observe when the neutron star magnetic field is > ∼ 10 14 G.

show abstract

Astrophysics of the Soft Gamma Repeaters and Anomalous X-Ray Pulsars

Abstract: I summarize recent developments in the magnetar model of the Soft Gamma Repeaters and Anomalous X-ray Pulsars, give a critical inventory of alternative models for the AXPs, and outline the improved diagnostics expected from present observational efforts.

Cited by 7 publications

References 80 publications

Neutron Stars—Cooling and Transport

Neutron Stars—Cooling and Transport

Neutron Stars—Cooling and Transport

Atmospheres of magnetized neutron stars: vacuum polarization and partially ionized models

Contact Info

Product

Resources

About