Related papers: Possible evidence for double precessing nozzle str…
We identify SDSS J153636.22+044127.0, a QSO discovered in the Sloan Digital Sky Survey, as a promising candidate for a binary black hole system. This QSO has two broad-line emission systems separated by 3500 km/sec. The redder system at…
On the kiloparsec scale, extragalactic radio jets show two distinct morphologies related to their power: collimated high-power jets ending in a bright termination shock and low-power jets opening up close to the core and showing a more…
In this brief note we point out that the four spatially resolved relativistic jets among the 14 dynamically confirmed black hole X-ray novae are all in systems with long orbital periods. Many shorter period systems show transient radio…
The dynamics of precessing binary black holes (BBHs) in the post-Newtonian regime has a strong timescale hierarchy: the orbital timescale is very short compared to the spin-precession timescale which, in turn, is much shorter than the…
We analyze all available RXTE data on a sample of 13 low mass X-ray binaries with known neutron star spin that are not persistent pulsars. We carefully measure the correlations between the centroid frequencies of the quasi-periodic…
Here we summarize our results from a detailed multi-frequency study of the QSO 3C309.1 based on the Very Long Baseline Array (VLBA) observations made in mid 1998. From our images, we find a curved jet extending up to 100 milliarcseconds…
The empirical relations in the black hole-accretion disk-relativistic jet system and physical processes behind these relations are still poorly understood, partly because they operate close to the black hole within the central light year.…
Motivated by recent accurate measurements of disk/jet coprecessions around some galactic supermassive black holes, the accelerations experienced by an uncharged, spinless object in the Kerr metric, written in harmonic coordinates, are…
We explore the relation between black hole mass ($M_{\rm BH}$) and the motion of the jet components for a sample of blazars. The Very Long Baseline Array (VLBA) 2cm Survey and its continuation: Monitoring of Jets in active galactic nuclei…
Allowing for the conical shape of ultrarelativistic blazar jets with opening angles of a few degrees on parsec-scales we show that their bulk Lorentz factors and viewing angles can be much larger than the values usually inferred by…
Velocity offsets in the broad Balmer lines of quasars and their temporal variations serve as indirect evidence for bound supermassive black hole binaries (SBHBs) at sub-parsec separations. In this work, we test the SBHB hypothesis for 14…
Blazars are a sub-population of quasars whose jets are nearly aligned with the line-of-sight, which tend to exhibit multi-wavelength variability on a variety of timescales. Quasi-periodic variability on year-like timescales has been…
The evolution of FRI jets has been long studied in the framework of the FRI-FRII dichotomy. In this paper, we test the present theoretical and observational models via a relativistic numerical simulation of the jets in the radio galaxy 3C…
We present the results of a multi-frequency analysis of the structural variability in the parsec-scale jet of the blazar S5 1803+784. More than 90 epochs of observations at 6 frequencies from 1.6 GHz up to 22 GHz have been combined and…
Context. Radio-loud AGNs with powerful relativistic jets are thought to be associated with rapidly spinning black holes (BHs). BH spin-up may result from a number of processes, including accretion of matter onto the BH itself, and…
We present a new method to fit the variations of both coordinates of a VLBI component as a function of time, assuming that the nucleus of the radio source contains a binary black hole system (BBH system). The presence of a BBH system…
Here we discuss two consecutive MERLIN observations of the X-ray binary LS I +61 303. The first observation shows a double-sided jet extending up to about 200 AU on both sides of a central source. The jet shows a bent S-shaped structure…
SS433 is a Galactic microquasar with powerful outflows (double jet, accretion disk and winds) with well known orbital, precessional and nutational period. In this work we characterise different outflow parameters throughout the precessional…
We study the general physical properties of Fermi blazars using the Fermi fourth source catalog data (4FGL-DR2). The quasi-simultaneous multiwavelength data of Fermi blazar are fitted by using the one-zone leptonic model to obtain some…
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…