Related papers: Radio quasars and the link with GAIA
We investigate the pc-scale kinematics and kpc-scale radio morphology of the quasar PG 1302-102, which may harbour a sub-pc separation supermassive binary black hole system at its centre as inferred from optical variability. High-resolution…
The highest-redshift quasars are still rare and valuable objects for observational astrophysics and cosmology. They provide important constraints on the growth of the earliest supermassive black holes in the Universe, and information on the…
This study uses multi-frequency Very Long Baseline Interferometry (VLBI) to study the radio emission from 10 radio-quiet quasars (RQQs) and four radio-loud quasars (RLQs). The diverse morphologies, radio spectra, and brightness temperatures…
We have examined a subset of 11 active galactic nuclei (AGN) drawn from a sample of 87 objects that possess double-peaked optical emission line spectra, as put forward by Wang et al. (2009a) and are detectable in the FIRST survey at radio…
Nearly a hundred of binary black holes (BBHs) have been discovered with gravitational-wave signals emitted at their merging events. Thus, it is quite natural to expect that significantly more abundant BBHs with wider separations remain…
We analysed the optical and radio properties of lobe-dominated giant-sized (> 0.72 Mpc) radio quasars and compared the results with those derived for a sample of smaller radio sources to determine whether the large size of some…
For a successful detection of gravitational waves by LISA, it is essential to construct theoretical waveforms in a reliable manner. We discuss gravitational waves from an extreme mass ratio binary system which is expected to be a promising…
The radio-emitting quasar SDSS J1425+3231 (z=0.478) was recently found to have double-peaked narrow [O III] optical emission lines. Based on the analysis of the optical spectrum, Peng et al. (2011) suggested that this object harbours a dual…
There is considerable evidence that powerful radio quasars and radio galaxies are orientation-dependent manifestations of the same parent population: massive spheroids containing correspondingly massive black holes. Following the…
A supermassive black hole binary may form during galaxy mergering. we investigate the interaction of the supermassive binary black holes (SMBBHs) and an accretion disk and show that the detected X-shaped structure in some FRII radio…
Discovery of gravitational waves by LIGO team (Abbott et al. 2016) bring a new era for observation of black hole systems. These new observations will improve our knowledge on black holes and gravitational physics. In this study, we present…
The radio source at the center of the cool core galaxy cluster RBS 797 (z=0.35) is known to exhibit a misalignment of its radio jets and lobes observed at different VLA-scale, with the innermost kpc-scale jets being almost orthogonal to the…
The quasar J1918+4937 was recently suggested to harbour a milliparsec-separation binary supermassive black hole (SMBH), based upon modeling the narrow spike in its high-cadence Kepler optical light curve. Known binary SMBHs are extremely…
We have searched the core-jets pairs in the VLBI scales ($<$1 kpc), from several VLBI catalogues, and find out 6 possible binary black hole (BBH) candidates. We present the search result and analyze the candidates preliminarily, and further…
We report on the discovery of a dual supermassive black hole system in the radio galaxy J1543-0757, with a projected separation between the two black holes of 46 mas. The result is based on recent multifrequency observations using the Very…
The Laser Interferometer Space Antenna (LISA) will produce a data stream containing a vast number of overlapping sources: from strong signals generated by the coalescence of massive black hole binary systems to much weaker radiation form…
Stellar-mass black hole binaries (BHBs) in galactic nuclei are gravitationally perturbed by the central supermassive black hole (SMBH) of the host galaxy, potentially inducing strong eccentricity oscillations through the eccentric…
Supermassive binary black holes (BBHs) on sub-parsec scales are prime targets for gravitational wave experiments. They also provide insights on close binary evolution and hierarchical structure formation. Sub-parsec BBHs cannot be spatially…
Supermassive binary black holes (SBBHs) are a natural outcome of galaxy mergers. Here we show that low-frequency ($f \leq 10^{-6}$ Hz) quasi-periodic variability observed from cosmic blazar sources can provide substantial inductive support…
In this chapter I will review the status of our phenomenological understanding of the relation between accretion and outflows in accreting black hole systems. This understanding arises primarily from observing the relation between X-ray and…