Accreting Schwarzschild-like compact object: Plasma-photon interaction and stability

Abstract

Accretion is a common phenomenon associated with any astrophysical compact object, which is best described by plasma, a state of matter composed of electrons and heavy ions. In this paper, we analyze the linear dynamics of electromagnetic (EM) fields propagating through the accreting plasma around static and spherically symmetric horizon-less, exotic compact objects (ECOs). The general equations governing the propagation of EM waves in such a background exhibit quasi-bound states whose characteristic frequencies differ from the BH values for both the axial and the polar modes, as well as for homogeneous and inhomogeneous plasma distributions. Moreover, the real and imaginary parts of these quasi-bound frequencies depict an oscillatory behaviour with the plasma frequency, characteristic of the ECOs considered. The amplitude of these oscillations depends on the non-zero reflectivity of the surface of the compact object, while the oscillation length depends on its compactness. This results in slower decay of the quasi-bound states with time for a certain parameter space of the plasma frequency, compared to BHs, making these ECOs more prone to instabilities.

20 pages, 7 figures, published in Phys. Rev. D

References in corpus (21)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• First Sagittarius A* Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole in the Center of the Milky Way
• Can environmental effects spoil precision gravitational-wave astrophysics?
• Echoes of ECOs: gravitational-wave signatures of exotic compact objects and of quantum corrections at the horizon scale
• First Sagittarius A* Event Horizon Telescope Results. V. Testing Astrophysical Models of the Galactic Center Black Hole
• First Sagittarius A* Event Horizon Telescope Results. III: Imaging of the Galactic Center Supermassive Black Hole
• Tests for the existence of horizons through gravitational wave echoes
• Open data from the third observing run of LIGO, Virgo, KAGRA and GEO
• A recipe for echoes from exotic compact objects
• Shadows of boson and Proca stars with thin accretion disks
• Imaging compact boson stars with hot-spots and thin accretion disks
• Tidal heating as a discriminator for horizons in extreme mass ratio inspirals
• Shadows and photon rings of regular black holes and geonic horizonless compact objects
• Review of the Advanced LIGO gravitational wave observatories leading to observing run four
• Observational properties of relativistic fluid spheres with thin accretion disks
• Observational imprints of gravastars from accretion disks and hot-spots
• Limits on stellar structures in Lovelock theories of gravity
• Dynamical Love for area quantized black holes
• Echoes from braneworld wormholes
• Galactic wormholes: Geometry, stability, and echoes
• Superradiant instabilities of massive bosons around exotic compact objects