Related papers: Twin jets as a potential distance detector
As the Universe expands, the redshift of distant sources changes with time. Here we discuss gravitational lensing phenomena that are consequence of the redshift drift between lensed source, gravitational lens, and observer. When the source…
Rapid variability on a time scale much faster than the light-crossing time of the central supermassive black hole has been seen in TeV emission from the blazar PKS 2155-304. The most plausible explanation of this puzzling observation is…
The distribution and orientation of energy inside jets is predicted to be an experimental handle on colour connections between the hard--scatter quarks and gluons initiating the jets. This Letter presents a measurement of the distribution…
We study the fluctuations of the light emitted by two identical incoherent point sources in a disordered environment. The intensity-intensity correlation function and the speckle contrast, obtained after proper temporal and configurational…
We focus in this paper in the estimation of a target trajectory defined by whether a time constant parameter in a simple stochastic process or a random walk with binary observations. The binary observation comes from binary derivative…
The cosmic distance scale is built on multiple different techniques for estimating distances in space that are often connected and dependent on multiple measurements and assumptions. Double white dwarf binaries (DWDs) are common objects and…
Astrophysical jets are often observed as bent or curved structures. We also know that the different jet sources may be binary in nature, which may lead to a regular, periodic motion of the jet nozzle, an orbital motion or precession. Here,…
Recently, Owen(1993) and Owen and Ledlow (1994) have shown that the dividing line between Fanaroff-Riley class~I and class~II Radio Sources is very sharp when the sources are represented as points in the radio-optical luminosity plane. It…
We report the first direct photon velocity measurements for extragalactic objects. A fiber-optic, photon time-of-flight instrument, optimized for relatively dim sources ($m 12$), is used to measure the velocity of visible photons emanating…
Context. Hypervelocity stars move fast enough to leave the gravitational field of their home galaxies and venture into intergalactic space. The most extreme examples known have estimated speeds in excess of 1000 km/s. These can be easily…
Although a system is described by a well-known set of equations leading to a deterministic behavior, in the real world the value of a measurand obtained by an experiment will mostly scatter. Accordingly, an uncertainty is associated with…
We present proper motions obtained from a dual frequency, six-epoch, VLBA polarization experiment monitoring a sample of 12 blazars. The observations were made at 15 GHz and 22 GHz at bi-monthly intervals over 1996. Ten of the eleven…
The lensing effect of a cosmic string is studied, and some new methods are proposed to detect the cosmic string. The technique for using jets as extended gravitational lensing probes was firstly explored by Kronberg. We use the…
Though widely observed to be emanating out from a variety of galactic and extra-galactic sources, the underlying physical mechanism behind the formation of the cosmic jets and outflows are wrapped around by the veil of mystery till date.…
The general expression of the angular distance between two point sources as measured by an arbitrary observer is given. The modelling presented here is rigorous, covariant and valid in any space-time. The sources of light may be located at…
We address the aircraft conflict resolution problem under trajectory prediction uncertainty. We consider that aircraft velocity vectors may be perturbed due to weather effects, such as wind, or measurement errors. Such perturbations may…
The relative transverse velocity of a lens with respect to the source star in gravitational lensing results in a frequency shift in the light rays passing by a lens. We propose using this relativistic effect for measuring the relative…
Studies of binary pulsars provide insight into various theories of physics. Detection of such systems is challenging due to the Doppler modulation of the pulsed signal caused by the orbital motion of the pulsar. We investigated the loss of…
Discrepancies of range between the Space Surveillance Network radars and the Deep Space Network in tracking the 1998 earth flyby of NEAR, and between ESA's Doppler and range data in Rosetta's 2009 flyby, reveal a consistent excess delay, or…
Entropy is the measure of uncertainty in any data and is adopted for maximisation of mutual information in many remote sensing operations. The availability of wide entropy variations motivated us for an investigation over the suitability…