Geometrically thick tori around compact objects with a quadrupole moment

Abstract

We study geometrically thick perfect-fluid tori with constant specific angular momentum, so-called "Polish doughnuts", orbiting deformed compact objects with a quadrupole moment. More specifically, we consider two different asymptotically flat, static and axisymmetric vacuum solutions to Einstein's field equation with a non-zero quadrupole moment, the q-metric and the Erez-Rosen spacetime. It is our main goal to find features of Polish doughnuts in these two spacetimes which qualitatively distinguish them from Polish doughnuts in the Schwarzschild spacetime. As a main result we find that, for both metrics, there is a range of positive (Geroch-Hansen) quadrupole moments which allows for the existence of double tori. If these double tori fill their Roche lobes completely, their meridional cross-section has the shape of a fish, with the body of the fish corresponding to the outer torus and the fish-tail corresponding to the inner torus. Such double tori do not exist in the Schwarzschild spacetime.

arXiv comment28 pages, 12 figures

References in corpus (8)

• Observation of Gravitational Waves from a Binary Black Hole Merger
• Motion of test particles in the field of a naked singularity
• Mass Quadrupole as a Source of Naked Singularities
• A stationary q-metric
• Ringed accretion disks: evolution of double toroidal configurations
• Relativistic thick accretion disks: morphology and evolutionary parameters
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• On Relativistic Multipole Moments of Stationary Spacetimes

Cited by in corpus (4)

• Equilibrium non-selfgravitating tori around black holes in parameterised spherically symmetric spacetimes
• Electromagnetic signatures of strong-field gravity from accreting black holes
• Light Deflection in Plasma in the Hartle-Thorne Metric and in Other Axisymmetric Spacetimes with a Quadrupole Moment
• Synchrotron emitting Komissarov torus around naked singularities