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Related papers: Interstellar Scintillation Observations of 146 Ext…

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The 4.9 GHz Micro-Arcsecond Scintillation-Induced Variability (MASIV) Survey detected a drop in Interstellar Scintillation (ISS) for sources at redshifts z > 2, indicating an apparent increase in angular diameter or a decrease in flux…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-09 J. Y Koay , J. -P. Macquart , B. J. Rickett , H. E. Bignall , J. E. J. Lovell , C. Reynolds , D. L. Jauncey , T. Pursimo , L. Kedziora-Chudczer , R. Ojha

We have conducted the first systematic search for interday variability in a large sample of extragalactic radio sources at 15 GHz. From the sample of 1158 radio-selected blazars monitored over a $\sim$10 year span by the Owens Valley Radio…

We investigate the relationship between 5 GHz interstellar scintillation (ISS) and 15 GHz intrinsic variability of compact, radio-selected AGNs drawn from the Microarcsecond Scintillation-Induced Variability (MASIV) Survey and the Owens…

Comparing the asymmetry coefficients and scintillation indices for observed time variations of the intensity of the radiation of extragalactic sources and the predictions of theoretical models is a good test of the nature of the observed…

Astrophysics · Physics 2009-11-11 V. I. Shishov , T. V. Smirnova , S. A. Tyul'bashev

The remarkable rapid variations in radio flux density and polarization of the quasar PKS 0405-385 observed in 1996 are subject to a correlation analysis, from which characteristic time scales and amplitudes are derived. The variations are…

Astrophysics · Physics 2009-11-07 Barney J. Rickett , Lucyna Kedziora-Chudczer , David L. Jauncey

We report on the variability of 443 flat spectrum, compact radio sources monitored using the VLA for 3 days in 4 epochs at ~ 4 month intervals at 5 GHz as part of the Micro-Arcsecond Scintillation-Induced Variability (MASIV) survey. Over…

Observations over the last two decades have shown that a significant fraction of all flat-spectrum, extragalactic radio sources exhibit flux density variations on timescales of a day or less at frequencies of several GHz. It has been…

The fraction of compact active galactic nuclei (AGNs) that exhibit interstellar scintillation (ISS) at radio wavelengths, as well as their scintillation amplitudes, have been found to decrease significantly for sources at redshifts z > 2.…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-14 J. Y. Koay , J. -P. Macquart , B. J. Rickett , H. E. Bignall , D. L. Jauncey , T. Pursimo , C. Reynolds , J. E. J. Lovell , L. Kedziora-Chudczer , R. Ojha

The search for compact components of strong ($S_{int} \ge 5$ Jy at 102.5 MHz) discrete radio sources from the Pushchino catalogue was carried out using the method of interplanetary scintillation. A total of 3620 sources were examined, and…

High Energy Astrophysical Phenomena · Physics 2022-07-18 S. A. Tyul'bashev , I. V. Chashei , I. A. Subaev , M. A. Kitaeva

We investigate the feasibility of detecting and probing various components of the ionized intergalactic medium (IGM) and their turbulent properties at radio frequencies through observations of scatter broadening of compact sources. There is…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-01 J. Y. Koay , J. -P. Macquart

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…

We present light curves for 149 sources monitored with the Green Bank Interferometer. The light curves are at two radio frequencies (approximately 2.5 and 8.2 GHz) and range from 3 to 15 yrs in length, covering the interval 1979--1996, and…

Intraday variability (IDV) of compact extragalactic radio sources is a complex phenomenon and shows a wavelength dependent mixture of refractive interstellar scintillation (RISS) (dominant at long cm-wavelengths) and source-intrinsic…

Astrophysics · Physics 2007-05-23 Giuseppe Cimò , L. Fuhrmann , T. P. Krichbaum , T. Beckert , A. Kraus , A. Witzel , J. A. Zensus

Interstellar scintillation can be used to probe transverse sizes of radio sources on scales inaccessible to the nominal resolution of any terrestrial telescope, e.g. $\lesssim 10^{-6}$ arc sec. Methodology is presented that exploits this…

Astrophysics · Physics 2007-05-23 J. M. Cordes

We are undertaking a large-scale, Micro-Arcsecond Scintillation-Induced Variability (MASIV) survey of the northern sky, Dec > 0 deg, at 4.9 GHz with the VLA. Our objective is to construct a sample of 100 to 150 scintillating extragalactic…

Interstellar scintillation (ISS) has been established as the cause of the random variations seen at centimetre wavelengths in many compact radio sources on timescales of a day or less. Observations of ISS can be used to probe structure both…

Context. Interstellar scintillation (ISS) of pulsar emission can be used both as a probe of the ionised interstellar medium (IISM) and cause corruptions in pulsar timing experiments. Of particular interest are so-called scintillation arcs…

We present the results of flux density monitoring of PSR B0329+54 at the frequency of 4.8 GHz using the 32-meter TCfA radiotelescope. The observations were conducted between 2002 and 2005. The main goal of the project was to find…

Astrophysics of Galaxies · Physics 2015-05-28 Wojciech Lewandowski , Jaroslaw Kijak , Yashwant Gupta , Krzysztof Krzeszowski

We present a catalogue of over 7000 sources from the GLEAM survey which have significant structure on sub-arcsecond scales at 162MHz. The compact nature of these sources was detected and quantified via their Interplanetary Scintillation…

Instrumentation and Methods for Astrophysics · Physics 2023-01-04 John Morgan , Rajan Chhetri , Ron Ekers

The search for long-term variability of compact components of radio sources B0821+394 and B1812+412 over an interval of 10 years was carried out. The LPA LPI radio telescope with an operating frequency of 111 MHz was used for observations.…

High Energy Astrophysical Phenomena · Physics 2025-04-16 S. A. Tyul'bashev , I. V. Chashei , I. A. Grishanova , G. E. Tyul'basheva , I. A. Subaev
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