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Related papers: A search for sub-second radio variability predicte…

200 papers

We present the results of a time series analysis of the long-term radio lightcurves of four blazars: 3C 279, 3C 345, 3C 446, and BL Lacertae. We exploit the data base of the University of Michigan Radio Astronomy Observatory (UMRAO)…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Jong-Ho Park , Sascha Trippe

We report the analysis of Fermi Large Area Telescope data from five years of observations of the broad line radio galaxy 3C 120. The accumulation of larger data set results in the detection of high-energy $\gamma$-rays up to 10 GeV, with a…

High Energy Astrophysical Phenomena · Physics 2015-02-04 N. Sahakyan , D. Zargaryan , V. Baghmanyan

Fast radio bursts are extragalactic, sub-millisecond radio impulses of unknown origin [1,2]. Their dispersion measures, which quantify the observed frequency-dependent dispersive delays in terms of free-electron column densities,…

High Energy Astrophysical Phenomena · Physics 2019-07-16 Vikram Ravi

A sample of 123 radio sources that exhibit significant variations at 1.4 GHz on a seven year base-line has been created using FIRST VLA B-array data from 1995 and 2002 on a strip at dec=0 near the south Galactic cap. This sample spans the…

Astrophysics · Physics 2009-11-10 W. H. de Vries , R. H. Becker , R. L. White , D. J. Helfand

Hubble Space Telescope images of 3CR radio galaxies at redshifts 0.6 < z < 1.8 have shown a remarkable variety of structures, generally aligned along the radio axis, indicating that the radio source strongly influences the optical…

Astrophysics · Physics 2009-10-30 P. N. Best , M. S. Longair , H. J. A. R"ottgering

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…

Solar and Stellar Astrophysics · Physics 2015-05-20 L. Cerrigone , C. Trigilio , G. Umana , C. S. Buemi , P. Leto

We studied the correlation between brightness and polarization variations in 3C~279 at different wavelengths, over time intervals long enough to cover the time lags due to opacity effects. We used these correlations together with VLBI…

High Energy Astrophysical Phenomena · Physics 2019-06-19 Pedro P. B. Beaklini , Tânia P. Dominici , Zulema Abraham , Juliana C. Motter

Metrewave solar type-III radio bursts offer a unique means to study the properties of turbulence across the coronal heights.Theoretical models have shown that the apparent intensity and size of the burst sources evolve at sub-second scales…

Solar and Stellar Astrophysics · Physics 2021-11-24 Atul Mohan

Using newly released data from the Wide-field Infrared Survey Explorer, we report the discovery of rapid infrared variability in three radio-loud narrow-line Seyfert 1 galaxies (NLS1s) selected from the 23 sources in the sample of Yuan et…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Ning Jiang , Hong-Yan Zhou , Luis C. Ho , Weimin Yuan , Ting-Gui Wang , Xiao-Bo Dong , Peng Jiang , Tuo Ji , Qiguo Tian

We summarize results from flux density monitoring campaigns performed with the 100 meter radio-telescope at Effelsberg and the VLA during the past 15 yrs. We briefly discuss some of the statistical properties of the rapid variability from…

Astrophysics · Physics 2009-11-07 T. P. Krichbaum , A. Kraus , L. Fuhrmann , G. Cimo , A. Witzel

Short time-scale radio variations of compact extragalactic radio quasars and blazars known as IntraDay Variability (IDV) can be explained in at least some sources as a propagation effect; the variations are interpreted as scintillation of…

Broad line radio galaxies (BLRGs) are a rare type of radio-loud AGN, in which the broad optical permitted emission lines have been detected in addition to the extended jet emission. Here we report on deep (40ksec x4) observations of the…

We report on an analysis of the Extended Chandra Deep Field South (E-CDFS) region using archival data from the Very Large Array, with the goal of studying radio variability and transients at the sub-mJy level. The 49 epochs of E-CDFS…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 K. P. Mooley , D. A. Frail , E. O. Ofek , N. A. Miller , S. R. Kulkarni , A. Horesh

We report multi-frequency observations of large radio galaxies 3C 35 and 3C 284. The low-frequency observations were done with Giant Metrewave Radio Telescope starting from $\sim150$ MHz, and the high-frequency observations were done with…

Astrophysics of Galaxies · Physics 2023-08-08 Dusmanta Patra , Sabyasachi Pal

We present results from a multi-year monitoring campaign of the broad-line radio galaxy 3C 120, using the Rossi X-ray Timing Explorer (RXTE) for nearly five years of observations. Additionally, we present coincident optical monitoring using…

This work presents the results from a systematic search for evidence of temporal changes (i.e., non-stationarity) associated with spectral variations in 3C 390.3, using data from a two-year intensive RXTE monitoring campaign of this…

Astrophysics · Physics 2009-11-11 M. Gliozzi , I. E. Papadakis , C. Raeth

We examine lengthy radio light curves of the flat spectrum radio galaxy 3C 454.3 for possible quasi-periodic oscillations (QPOs). The data used in this work were collected at five radio frequencies, 4.8, 8.0, 14.5, 22.0, and 37.0 GHz…

In the time domain, the radio sky in particular along the Galactic plane direction may vary significantly because of various energetic activities associated with stars, stellar and supermassive black holes. Using multi-epoch Very Large…

High Energy Astrophysical Phenomena · Physics 2022-01-12 Jun Yang , Yongjun Chen , Leonid I. Gurvits , Zsolt Paragi , Aiyuan Yang , Xiaolong Yang , Zhiqiang Shen

Many of the powerful radio galaxies observed at high redshift are very small, presumably because they are very young. A simple model, which treats the radio source as a bubble expanding into a radially stratified medium, is capable of…

Astrophysics · Physics 2007-05-23 Mitchell C. Begelman

Recent investigations of how the median size of extragalactic radio sources change with redshift have produced inconsistent results. Eales compared the radio and optical properties of a bright 3C and faint 6C sample and concluded that…