English

On the last stable orbit around rapidly rotating neutron stars

High Energy Astrophysical Phenomena 2017-08-09 v3 Solar and Stellar Astrophysics General Relativity and Quantum Cosmology

Abstract

We compute the binding energy and angular momentum of a test-particle at the last stable circular orbit (LSO) on the equatorial plane around a general relativistic, rotating neutron star (NS). We present simple, analytic, but accurate formulas for these quantities that fit the numerical results and which can be used in several astrophysical applications. We demonstrate the accuracy of these formulas for three different equations of state (EOS) based on nuclear relativistic mean-field theory models and argue that they should remain still valid for any NS EOS that satisfy current astrophysical constraints. We compare and contrast our numerical results with the corresponding ones for the Kerr metric characterized by the same mass and angular momentum.

Keywords

Cite

@article{arxiv.1612.02207,
  title  = {On the last stable orbit around rapidly rotating neutron stars},
  author = {Federico Cipolletta and Christian Cherubini and Simonetta Filippi and Jorge A. Rueda and Remo Ruffini},
  journal= {arXiv preprint arXiv:1612.02207},
  year   = {2017}
}

Comments

Accepted for publication in Phys. Rev. D