The final stages of accretion onto non-Kerr compact objects

Abstract

The $5-20M_{\odot }$ dark objects in X-ray binary systems and the $10^5-10^9{M}_{\odot }$ dark objects in galactic nuclei are currently thought to be the Kerr black holes predicted by General Relativity. However, direct observational evidence for this identification is still elusive, and the only viable approach to confirm the Kerr black hole hypothesis is to explore and rule out any other possibility. Here we investigate the final stages of the accretion process onto generic compact objects. While for Kerr black holes and for more oblate bodies the accreting gas reaches the innermost stable circular orbit (ISCO) and plunges into the compact object, we find that for more prolate bodies several scenarios are possible, depending on the spacetime geometry. In particular, we find examples in which the gas reaches the ISCO, but then gets trapped between the ISCO and the compact object. In this situation, accretion onto the compact object is possible only if the gas loses additional angular momentum, forming torus-like structures inside the ISCO.

13 pages, 4 figures. v2: some typos corrected

References in corpus (24)

• Apparent shape of super-spinning black holes
• Null geodesics and shadow of a rotating black hole in extended Chern-Simons modified gravity
• How to tell a gravastar from a black hole
• Using LISA EMRI sources to test off-Kerr deviations in the geometry of massive black holes
• Testing the general relativistic ''no-hair'' theorems using the galactic center black hole SgrA*
• Thin accretion disks in stationary axisymmetric wormhole spacetimes
• Ergoregion instability of ultra-compact astrophysical objects
• Bumpy Black Holes in Alternate Theories of Gravity
• Observable Properties of Orbits in Exact Bumpy Spacetimes
• Extreme- and Intermediate-Mass Ratio Inspirals in Dynamical Chern-Simons Modified Gravity
• Shape and position of the shadow in the $\delta =2$ Tomimatsu-Sato space-time
• Can accretion disk properties distinguish gravastars from black holes?
• The influence of the hydrodynamic drag from an accretion torus on extreme mass-ratio inspirals
• Perturbed Kerr Black Holes can probe deviations from General Relativity
• How to observe a non-Kerr spacetime
• Forced motion near black holes
• Gravitational waves from Extreme Mass Ratio Inspirals in non-pure Kerr spacetimes
• Dynamics of magnetized relativistic tori oscillating around black holes
• Thin accretion disk signatures of slowly rotating black holes in Hořava gravity
• Supermassive black holes or boson stars? Hair counting with gravitational wave detectors
• Constraint on the quadrupole moment of super-massive black hole candidates from the estimate of the mean radiative efficiency of AGN
• (Sort of) Testing relativity with extreme mass ratio inspirals
• Evolution of the spin parameter of accreting compact objects with non-Kerr quadrupole moment
• Spinning super-massive objects in galactic nuclei up to $a_{\ast }>1$

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• Slowly Rotating Black Holes in Dynamical Chern-Simons Gravity: Deformation Quadratic in the Spin
• Slowly-Rotating Black Holes in Einstein-Dilaton-Gauss-Bonnet Gravity: Quadratic Order in Spin Solutions
• A code to compute the emission of thin accretion disks in non-Kerr space-times and test the nature of black hole candidates
• Testing the space-time geometry around black hole candidates with the analysis of the broad K$\alpha$ iron line
• Probing the space-time geometry around black hole candidates with the resonance models for high-frequency QPOs and comparison with the continuum-fitting method
• Black holes in Lorentz-violating gravity theories
• Testing the Kerr black hole hypothesis
• Testing the no-hair theorem with the continuum-fitting and the iron line methods: a short review
• Testing the Kerr-nature of stellar-mass black hole candidates by combining the continuum-fitting method and the power estimate of transient ballistic jets
• Dynamics of a Charged Particle Around a Slowly Rotating Kerr Black Hole Immersed in Magnetic Field
• Systematic Study of Event Horizons and Pathologies of Parametrically Deformed Kerr Spacetimes
• NR/HEP: roadmap for the future
• Direct imaging rapidly-rotating non-Kerr black holes
• Accretion disks around the Gibbons-Maeda-Garfinkle-Horowitz-Strominger charged black holes
• Towards the use of the most massive black hole candidates in AGN to test the Kerr paradigm
• Charged particle motion around a quasi-Kerr compact object immersed in an external magnetic field
• Hairy Black Holes: Non-existence of Short Hairs and Bound on Light Ring Size
• Dynamics of charged particles and magnetic dipoles around magnetized quasi-Schwarzschild black holes
• Testing the existence of regions of stable orbits at small radii around black hole candidates
• Properties of a thin accretion disk around a rotating non-Kerr black hole
• Super-spinning compact objects generated by thick accretion disks
• Accretion disk around the rotating Damour-Solodukhin wormhole
• Relativistic thick accretion disks: morphology and evolutionary parameters
• Quasi-normal modes of non-separable perturbation equations: the scalar non-Kerr case
• A parametrization to test black hole candidates with the spectrum of thin disks
• Weak gravitational lensing: a compact object with arbitrary quadrupole moment immersed in plasma
• Periodic Orbits and Escapes in Dynamical Systems
• Dynamics of charged particles moving around Kerr black hole with inductive charge and external magnetic field
• Inner Accretion Disk Edges in a Kerr-Like Spacetime
• Accretion disks around a static black hole in $f(R)$ gravity
• Possible signatures of higher dimension in thin accretion disk around brane world black hole
• Testing a class of non-Kerr metrics with hot spots orbiting SgrA${}^{\ast }$
• Measuring deviations from the Kerr geometry with black hole ringdown
• Accretion flow in deformed Kerr spacetime: Spectral energy distributions from free-free emission
• Black holes in General Relativity and beyond
• Observational properties of black hole in quantum fluctuation modified gravity
• Mind the Resonances: Final stages of accretion into bumpy black holes
• Tests of General Relativity using black hole X-ray data
• Observations of General Relativity at strong and weak limits
• Testing General Relativity with Black Hole X-Ray Data and ABHModels