Related papers: Proper motion of reference radio sources
We simulate the astrometric observations of stars moving close to the black hole in the Galactic Center. We show, that for orbits =<1000 AU and position measurements with the accuracy of the Keck Interferometer, the periastron motion of…
We perform three-dimensional numerical simulations of relativistic (with a Lorentz factor of 10), non magnetized jets propagating in a uniform density environment, in order to study the effect of the entrainment and the consequent…
We observed Sgr A* and two extragalactic radio sources nearby in angle with the VLBA over a period of two years and measured relative positions with an accuracy approaching 0.1 mas. The apparent proper motion of Sgr A* relative to J1745-283…
We report on a multi-frequency, multi-epoch campaign of Very Long Baseline Interferometry observations of the radio galaxy 1946+708 using the VLBA and a Global VLBI array. From these high-resolution observations we deduce the kinematic age…
Duration and period of transits in extrasolar planetary systems can exhibit long-term variations for a variety of reasons. Here we investigate how systemic proper motion, which steadily re-orients planetary orbit with respect to our line of…
We present proper motion of the sub-parsec scale jet in a nearby elliptical galaxy 3C 66B. Observations were made using the VLBA and partly Effelsburg 100-m telescope at 2.3 GHz and 8.4 GHz at 10 epochs over 4 years. The 8.4 GHz images…
It is shown that the relativistic jet, emitted from the center of the Galaxy during its activity, possessed power and energy spectrum of accelerated protons sufficient to explain the current cosmic rays distribution in the Galaxy. Proton…
Non-spherical rapid acceleration of mass (or energy) to a relativistic velocity is a natural source of gravitational radiation. Such conditions arise in both long and short gamma-ray bursts whose central engine ejects relativistic jets. The…
We have investigated a frequency-dependent shift in the absolute position of the optically thick apparent origin of parsec-scale jets ("core shift" effect) to probe physical conditions in ultra-compact relativistic outflows in AGN. We used…
Relativistic jets carry a significant fraction of the total energy budget of a radio source, rivaling the power that is extracted through accretion. A minor part of this bulk kinetic power is transformed to radiation, possibly through…
We have carried out relativistic three-dimensional simulations of high-power radio sources propagating into asymmetric cluster environments. We offset the environment by 0 or 1 core radii (equal to 144 kpc), and incline the jets by 0, 15,…
The apparent position of the "core" in a parsec-scale radio jet (a compact, bright emitting region at the narrow end of the jet) depends on the observing frequency, owing to synchrotron self-absorption and external absorption. While…
The kinematics of jets in active galactic nuclei (QSOs, BL Lacs, Radio Galaxies and Empty Field objects) on parsec scales is being studied with Very Long Baseline Array observations at 15 GHz of a sample of more than 170 radio sources. More…
We consider a possibility of detecting the jitter effect of apparent celestial positions of distant sources due to local fluctuations of the Galaxy gravitational field. It is proposed to observe two samples of extragalactic sources (target…
We consider the radiation pressure instability operating on short timescales 10^3 - 10^6 years in the accretion disk around a supermassive black hole as the origin of the intermittent activity of radio sources. We test whether this…
Collimated outflows (jets) appear to be a ubiquitous phenomenon associated with the accretion of material onto a compact object. Despite this ubiquity, many fundamental physics aspects of jets are still poorly understood and constrained.…
Microquasars are binary systems in our Galaxy which sporadically eject matter at relativistic speeds along bipolar jets. While phenomenologically similar to quasars, their vicinity allows much more in-depth studies. I review the…
There is a growing population of relativistically relevant minor bodies in the Solar System and a growing population of massive extrasolar planets with orbits very close to the central star where relativistic effects should have some…
The recent improvement in VLBI arrays is providing information of the emission and magnetic field structure of relativistic jets, both extragalactic and galactic (microquasars), with unprecedented spatial and temporal resolution. These…
The apparent position of the origin (core) of extragalactic radio jets shifts with the observing frequency, owing to synchrotron self-absorption and external absorption. One of the largest core shifts was detected by us in the quasar…