Do triaxial supramassive compact stars exist?

Abstract

We study quasiequilibrium solutions of triaxially deformed rotating compact stars -- a generalization of Jacobi ellipsoids under relativistic gravity and compressible equations of state (EOS). For relatively stiff (piecewise) polytropic EOSs, we find supramassive triaxial solutions whose masses exceed the maximum mass of the spherical solution, but are always lower than those of axisymmetric equilibriums. The difference in the maximum masses of triaxial and axisymmetric solutions depends sensitively on the EOS. If the difference turns out to be only about 10%, it will be strong evidence that the EOS of high density matter becomes substantially softer in the core of neutron stars. This finding opens a novel way to probe phase transitions of high density nuclear matter using detections of gravitational waves from new born neutron stars or magnetars under fallback accretion.

5 pages, 3 figures. Revised version to appear in PRD rapid communication

References in corpus (4)

• Constraints on a phenomenologically parameterized neutron-star equation of state
• Densities of Solar System Objects from their Rotational Lightcurves
• Quasi-equilibrium models for triaxially deformed rotating compact stars
• Viscosity driven instability in rotating relativistic stars

Cited by in corpus (11)

• Rotating Stars in Relativity
• Modeling differential rotations of compact stars in equilibriums
• New code for equilibriums and quasiequilibrium initial data of compact objects. IV. Rotating relativistic stars with mixed poloidal and toroidal magnetic fields
• Uniformly rotating, axisymmetric and triaxial quark stars in general relativity
• Constant circulation sequences of binary neutron stars and their spin characterization
• Evolution of bare quark stars in full general relativity: Single star case
• Gravitational wave content and stability of uniformly, rotating, triaxial neutron stars in general relativity
• Methods for relativistic self-gravitating fluids: From binary neutron stars to black hole-disks and magnetized rotating neutron stars
• The Parallel Compact Object CALculator: An Efficient General Relativistic Initial Data Solver for Compact Objects
• Triaxial instabilities in rapidly rotating Neutron Stars
• General Relativistic Stability and Gravitational Wave Content of Rotating Triaxial Neutron Stars