Related papers: A super massive black hole binary in 3C66B: future…
We analyze triple systems composed of the super massive black hole (SMBH) near the center of M87 and a pair of black holes (BHs) with masses in the range $10-10^3$ $M_{\odot}$. We consider the post Newtonian precession as well as the…
Coalescence of binary supermassive black holes (SBHs) would constitute the strongest sources of gravitational waves to be observed by LISA. While the formation of binary SBHs during galaxy mergers is almost inevitable, coalescence requires…
Direct imaging of black hole shadow halos has firmly confirmed the existence of supermassive black holes (SMBHs), with millions of solar masses, residing at the centers of the Milky Way and M87 galaxies. These groundbreaking discoveries…
Recent theoretical studies suggest that stellar-mass binary black holes (BBHs) would merge more efficiently due to the Kozai-Lidov mechanism if these binaries form in the vicinity of supermassive black holes (SMBHs). Since SMBHs are likely…
In several previous studies, quasars exhibiting broad emission lines with >1000 km/s velocity offsets with respect to the host galaxy rest frame have been discovered. One leading hypothesis for the origin of these velocity-offset broad…
Although supermassive black holes (SMBHs) correlate well with their host galaxies, there is an emerging view that outliers exist. Henize 2-10, NGC 4889, and NGC1277 are examples of SMBHs at least an order of magnitude more massive than…
We present a systematic search for periodically varying quasar and supermassive black hole binary (SMBHB) candidates in the Pan-STARRS1 Medium Deep Survey. From $\sim9,000$ color-selected quasars in a $\sim50$ deg$^{2}$ sky area, we…
Recent studies have proposed that GRAVITY+ instrument is able to trace the circular orbit of the subparsec close-binary supermassive black holes (CB-SMBHs) by measuring the photocentre variation of the hot dust emission. However, the…
During a galaxy merger, the supermassive black hole (SMBH) in each galaxy is thought to sink to the center of the potential and form a supermassive black hole binary; this binary can eject stars via 3-body scattering, bringing the SMBHs…
Theory predicts that a supermassive black hole binary (SMBHB) could be observed as a luminous active galactic nucleus (AGN) that periodically varies on the order of its orbital timescale. In X-rays, periodic variations could be caused by…
Most large galaxies host supermassive black holes in their nuclei and are subject to mergers, which can produce a supermassive black hole binary (SMBHB), and hence periodic signatures due to orbital motion. We report unique periodic radio…
We model for the first time the complete orbital evolution of a pair of Supermassive Black Holes (SMBHs) in a 1:10 galaxy merger of two disk dominated gas-rich galaxies, from the stage prior to the formation of the binary up to the onset of…
Supermassive black holes (SMBHs) are found at the centre of every massive galaxy, with their masses tightly connected to their host galaxies through a co-evolution over cosmic time. For massive ellipticals, the SMBH mass ($M_\text{BH}$)…
Observational measurements of the relationship between supermassive black holes (SMBHs) and the properties of their host galaxies are an important method for probing theoretical hierarchical growth models. Gravitational lensing is a unique…
We recently discovered a supermassive black hole binary (SMBHB) candidate, PKS J1309+1154, in the combined 46-yr University of Michigan Radio Astronomy Observatory (UMRAO) plus Owens Valley Radio Observatory (OVRO) blazar monitoring…
Supermassive black hole (SMBH) binaries with masses of ~10^8--10^9 Msun are expected to dominate the contribution to the as-yet undetected gravitational wave background (GWB) signal at the nanohertz frequencies accessible to Pulsar Timing…
The gravitational-wave background from supermassive binary black holes (SMBBHs) has yet to be detected. This has led to speculations as to whether current pulsar timing array limits are in tension with theoretical predictions. In this…
We propose a new spectral signature for supermassive black hole binaries (SMBHBs) with circumbinary gas disks: a sharp drop in flux blueward of the Lyman limit. A prominent edge is produced if the gas dominating the emission in the Lyman…
Rotating black holes can generate boson clouds via superradiance when the boson's Compton wavelength is comparable to the black hole's size. In binary systems, these clouds can produce distinctive observational imprints. Recent studies…
Supermassive black hole binaries (SMBHBs) are products of galaxy mergers, and are important in testing Lambda cold dark matter cosmology and locating gravitational-wave-radiation sources. A unique electromagnetic signature of SMBHBs in…