Neutron Stars 1: Equation of State and Structure

We present results from the JINA REACLIB project, an ongoing effort to maintain a current and accurate library of thermonuclear reaction rates for astrophysical applications. Ongoing updates are transparently documented and version tracked, and any set of rates is publicly available and can be downloaded via a Web interface at http://groups.nscl.msu.edu/jina/reaclib/db/. We discuss here our library V1.0, a snapshot of recommended rates for stable and explosive hydrogen and helium burning. We show that the updated reaction rates lead to modest but significant changes in full network, one-dimensional X-ray burst model calculations, compared with calculations with previously used reaction rate sets. The late time behavior of X-ray burst light curves shows significant changes, suggesting that the previously found small discrepancies between model calculations and observations may be solved with a better understanding of the nuclear input. Our X-ray burst model calculations are intended to serve as a benchmark for future model comparisons and sensitivity studies, as the complete underlying nuclear physics is fully documented and publicly available.

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The jina reaclib database: its recent updates and impact on type-i x-ray bursts

There is a wide range of fundamental physical problems directly related to how pulsars function. Some of these are independent of the specific pulsar mechanism. Others relate directly to the physics of the pulsar and already shed some light on the properties of matter at high density (\ensuremath{\sim}${10}^{15}$ g/cc) and in strong magnetic fields (\ensuremath{\sim}${10}^{12}$ G). Pulsars are assumed to be rotating neutron stars surrounded by strong magnetic fields and energetic particles. It is somewhere within this "magnetosphere" that the pulsar action is expected to take place. Currently there has been considerable difficulty in formulating an entirely self-consistent theory of the magnetospheric behavior and there may be rapid revisions in the near future, which is all the more surprising since many of the issues involve "elementary" problems in electromagnetism. One interesting discovery is that charge-separated plasmas apparently can support stable static discontinuities.

Theory of pulsar magnetospheres

X-ray bursts

https://www.cns.s.u-tokyo.ac.jp/~shimoura/research/nuc_data/pdf/11.pdf

Energy levels of light nuclei A = 11-12

It is proposed that γ-ray bursts originate from carbon detonations initiated by the accretion of matter on to the surface of a neutron star. The observations are interpreted in terms of this theory. Possible implications for the nuclear powered model of giant X-ray pulses are discussed briefly.

Ronald E. Taam

Papers

γ-ray bursts from thermonuclear explosions on neutron stars