相关论文: Exploring black holes with multiple photon spheres…
Classical black holes contain a singularity at their core. This has prompted various researchers to propose a multitude of modified spacetimes that mimic the physically observable characteristics of classical black holes as best as…
Thanks for the releasing image of supermassive black holes (BHs) by the event horizon telescope (EHT) at the heart of the $M87$ galaxy. After the discovery of this mysterious object, scientists paid attention to exploring the BH shadow…
Recently, asymptotically-flat black holes with multiple photon spheres have been discovered and found to produce distinctive observational signatures. In this paper, we focus on whether these black hole solutions are physically viable,…
From an astrophysical perspective, the composition of black holes (BHs), dark matter (DM), and dark energy can be an intriguing physical system. In this study, we consider Schwarzschild BHs embedded in a Dehnen-type DM halo exhibiting a…
In this paper, we investigate the optical behaviors of a quantum Schwarzschild black hole with a spacetime solution including a parameter $\lambda$ that encodes its discretization. Concretly, we derive the effective potential of such…
We model the electromagnetic emission signatures of massive black hole binaries (MBHBs) with an associated gas component. The method comprises numerical simulations of relativistic binaries and gas coupled with calculations of the physical…
Radial velocity monitoring has revealed the presence of moving broad emission lines in some quasars, potentially indicating the presence of a sub-parsec binary system. Phase-referenced, near-infrared interferometric observations could map…
The images of supermassive black holes in M87 and our galaxy captured by the Event Horizon Telescope (EHT) might open up a new way for exploring black hole physics at the horizon scale. Theoretically, this could provide insights into…
Currently envisioned extensions of the Event Horizon Telescope to space will soon target the black hole photon ring: a narrow ring-shaped imprint of a black hole's strong gravity produced in its images by highly bent photon trajectories. In…
Light passing near a black hole can follow multiple paths from an emission source to an observer due to strong gravitational lensing. Photons following different paths take different amounts of time to reach the observer, which produces an…
Two critical aspects of radio interferometric imaging analysis are data calibration and deconvolution of the point spread function (PSF) structure. Both of these are particularly important for high-frequency observations using a VLBI…
Horizons and bound photon orbits are defining features of black holes that translate into key features of black hole images. We present a purely geometric proof that spherically symmetric, isolated objects with horizons in gravity theories…
The optical appearance of a body compact enough to feature an unstable bound orbit, when surrounded by an accretion disk, is expected to be dominated by a luminous ring of radiation enclosing a central brightness depression typically known…
We investigate asymptotic Schwarzschild exterior solutions in the context of modified gravity theories, specifically within the framework of $f(R)$ gravity, where the asymptotic behavior recovers the standard Schwarzschild solution of…
Hierarchical structure formation inevitably leads to the formation of supermassive binary black holes (BBHs) with a sub-parsec separation in galactic nuclei. However, to date there has been no unambiguous detection of such systems. In an…
We test the potential of Bayesian synthesis of upcoming multi-instrument data to extract orbital parameters and individual light curves of close binary supermassive black holes (CB-SMBH) with subparsec separations. Next generation (ng)…
This study investigates polarized images of an equatorial synchrotron-emitting ring surrounding hairy black holes within the Einstein-Maxwell-scalar theory. Our analysis demonstrates qualitative similarities between the polarization…
In this paper, the optical effects that occur near a Schwarzschild-like black hole (BH) with a Dehnen-type $(1,4,2)$ dark matter (DM) halo are explored. We first derive the photon sphere radius and obtain an analytical expression for the…
Astrophysical black holes (BHs) are universally expected to be described by the Kerr metric, a stationary, vacuum solution of general relativity (GR). Indeed, by imaging M87$^\star$ and Sgr A$^\star$ and measuring the size of their shadows,…
Most large galaxies harbor supermassive black holes (SMBHs) in their centers, and galaxies merge. Consequently, binary SMBHs should be common in galactic nuclei. However, close binaries of SMBH (CB-SMBHs) with sub-parsec separation cannot…