Related papers: Interstellar scintillation as a probe of microarcs…
Extreme Scattering Events (ESEs) are dramatic variations of the flux density at Gigahertz frequencies caused by ray path distortions within an isolated inhomogeneity ("plasma lens") in the interstellar medium. These events are characterized…
We observed the scintillation pattern of nine bright pulsars at 324 MHz and three at 1.68 GHz and analyzed the wavenumber spectrum which is related to electron density variations of the plasma turbulence of the interstellar medium. For all…
An observer, situated several thousand light-years away from a radio pulsar, finds himself embedded in the diffraction pattern resulting from the propagation of the radio waves through the irregular interstellar medium. The observer's…
Two dozens of radio loud active galactic nuclei (AGNs) have been observed with Urumqi 25 m radio telescope in order to search for intra-day variability (IDV). The target sources are blazars (namely flat spectrum radio quasars and BL Lac…
We present results of observation of Cygnus-A radiosource scintillation in the Earth's ionosphere in quiet and disturbed geomagnetic condition at Irkutsk incoherent scattering radar (IISR). Scintillation method applied for ionosphere…
We have detected a strong deflection of radio waves from the pulsar PSR B0834+06 in scintillation observations. Interference between the undeflected pulsar image and deflected subimages allows single dish interferometry of the interstellar…
I suggest that radio-wave scattering by the interstellar plasma, in combination with subsonic gradients in the Doppler velocity of interstellar HI, is responsible for the observed small-scale variation in HI absorption spectra of pulsars.…
This paper presents the first high-resolution and high-sensitivity study of the radio properties of optically selected type~2 quasars. We used the Very Large Array at 8.4 GHz to observe 59 sources drawn from the Sloan Digital Sky Survey…
Observations of Interplanetary Scintillation (IPS) are an efficient remote-sensing method to study the solar wind and inner heliosphere. From 2016 to 2018, some distinctive observations of IPS sources like 3C 286 and 3C 279 were…
Interstellar turbulence has implications for the dispersal and mixing of the elements, cloud chemistry, cosmic ray scattering, and radio wave propagation through the ionized medium. This review discusses the observations and theory of these…
We present the results of an Australia Telescope Compact Array (ATCA) survey for intra-day variability (IDV) of the total and polarized flux densities of 118 compact, flat spectrum, extragalactic radio sources from the Parkes 2.7 GHz…
The interstellar scattering responsible for pulsar parabolic arcs, and for intra-day variability of compact radio quasars, is highly anisotropic in some cases. We numerically simulate these observed phenomena using totally anisotropic,…
Stars twinkle to the eye through atmospheric turbulence, but planets, because of their larger angular size, do not. Similarly, scintillation due to the local interstellar medium will modulate the radio flux of gamma-ray-burst afterglows and…
Radio variability in quasars has been seen on timescales ranging from days to years due to both intrinsic and propagation induced effects. Although separating the two is not always straight-forward, observations of singular `events' in…
Searching for variability, we have observed a sample of hot post-AGB stars and young Planetary Nebulae candidates with the Very Large Array at 4.8, 8.4, and 22.4 GHz. The sources had been previously detected in the radio continuum, which is…
Twenty five low redshift quasars have been monitored for several decades at five near- and mid-infrared wavelengths to detect rapid variations which would indicate that a nonthermal component was present in the "10 micron bump". Such…
We have performed a search over 3440 deg$^2$ of Epoch 1 (2017-2019) of the Very Large Array Sky Survey to identify unobscured quasars in the optical ($0.2 < z < 3.2$) and obscured active galactic nuclei (AGN) in the infrared that have…
Quasars are variable and their variability can both constrain their physical properties and help to identify them. We look for ways to efficiently identify quasars exhibiting consistent variability over multi-year time-scales, based on a…
We use data on extreme radio scintillation to demonstrate that this phenomenon is associated with hot stars in the solar neighbourhood. The ionized gas responsible for the scattering is found at distances up to 1.75pc from the host star,…
3C 286, a well-known radio calibrator, exhibits the stability in both of total flux density (FD) and polarization parameters. However, its stable and luminous interstellar radio signal may encounter interplanetary scintillation (IPS) due to…