Related papers: J1128+592: a highly variable IDV source
The most heavily polluted white dwarfs often show excess infrared radiation from circumstellar dust disks, which are modeled as a result of tidal disruption of extrasolar minor planets. Interaction of dust, gas, and disintegrating objects…
A subset of magnetic stars exhibit periodic radio pulses produced by the coherent electron cyclotron maser mechanism. These pulses are known to exhibit both temporal and spectral variations, which have been attributed to phenomena intrinsic…
We report radio observations of the quasar PMN J1106-3647. Our data, taken with the Australia Telescope Compact Array, show large variations in the amplitude and shape of its spectrum, on a short time-scale. A great variety of spectral…
We demostrate that the measurement of fluctuations of polarization due to the galactic interstellar scintillations may be used to study the structure of the radiation field at compact radio sources. We develop a mathematical formalism and…
An in-depth analysis of variability has been carried out on the 2 GHz and 8 GHz light curves from the impressive database of the US Navy's extragalactic source monitoring program at the Green Bank Interferometer (GBI), complemented by UMRAO…
We investigate the variability of exoplanetary radio emission using stellar magnetic maps and 3D field extrapolation techniques. We use a sample of hot Jupiter hosting stars, focusing on the HD 179949, HD 189733 and tau Boo systems. Our…
Studying the long-term radio variability (timescales of months to years) of blazars enables us to gain a better understanding of the physical structure of these objects on sub-parsec scales, and the physics of super massive black holes. In…
We present multi-frequency simultaneous VLBI radio observations of the flat spectrum radio quasar 1633+382 (4C~38.41) as part of the interferometric monitoring of gamma-ray bright active galactic nuclei (iMOGABA) program combined with…
The origin and physics of X-ray intra-day variability (IDV) in blazars, which is a long-standing issue, is studied by modelling the broad-band X-ray spectrum, the light curves (LCs), and the Fourier time lags. We present the timing analysis…
The mJy variable extragalactic radio sky is known to be broadly non-changing with approximately $3\%$ of persistent radio sources exhibiting variability which is largely AGN-related. In the faint (<mJy) flux density regime, it is widely…
We studied the turbulence spectrum of the local interstellar plasma in the direction of PSR J0437-4715, on the basis of our observations and those reported earlier by others. We combine these data to form a structure function for the…
We report on a blind survey for extragalactic radio variability that was carried out by comparing two epochs of data from the FIRST survey with a third epoch from a new 1.4 GHz survey of SDSS Stripe 82. The three epochs are spaced seven…
High-redshift blazars are one of the most powerful monsters in the universe and $\gamma$-ray variability carries crucial information of their relativistic jets. In this work we present results of the first systematical temporal analysis of…
The transient black hole binary XTE J1118+480 exhibited dramatic rapid variability at all wavelengths which were suitably observed during its 2000 April-July outburst. We examine time-resolved X-ray, ultraviolet, optical, and infrared data…
We have carried out a multifrequency analysis of the radio variability of blazars, exploiting the data obtained during the extensive monitoring programs carried out at the University of Michigan Radio Astronomy Observatory (UMRAO, at 4.8,…
Following an extensive survey of the galactic plane by the INTEGRAL satellite, new hard X-ray sources are discovered with a significant fraction of Cataclysmic Variables (CVs) among them. We report here the identification of one of these…
From 1979--1996 the Green Bank Interferometer was used by the Naval Research Laboratory to monitor the flux density from 146 compact radio sources at frequencies near 2 and 8 GHz. We filter the ``light curves'' to separate intrinsic…
Ten very low luminosity objects were observed multiple times in the 8.5 GHz continuum in search of protostellar magnetic activities. A radio outburst of IRAM 04191+1522 IRS was detected, and the variability timescale was about 20 days or…
We present a search for transient and variable radio sources at 154 MHz with the Murchison Widefield Array 32-tile prototype. Fifty-one images were obtained that cover a field of view of 1430 deg^2 centred on Hydra A. The observations were…
We present radio observations at three frequencies and contemporaneous optical monitoring of the peculiar BL Lac object AO 0235+164. During a three-week campaign with the VLA we observed intraday variability in this source and found a…