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相关论文: VLBI properties of compact interplanetary scintill…

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We report the first astrophysical application of the technique of wide-field Interplanetary Scintillation (IPS) with the Murchison Widefield Array (MWA). This powerful technique allows us to identify and measure sub-arcsecond compact…

高能天体物理现象 · 物理学 2018-01-10 R. Chhetri , J. Morgan , R. D. Ekers , J-P Macquart , E. M. Sadler , M. Giroletti , J. R. Callingham , S. J. Tingay

We use Murchison Widefield Array observations of interplanetary scintillation (IPS) to determine the source counts of point ($<$0.3 arcsecond extent) sources and of all sources with some subarcsecond structure, at 162 MHz. We have developed…

星系天体物理 · 物理学 2018-07-11 R. Chhetri , R. D. Ekers , J. Morgan , J. -P. Macquart , T. M. O. Franzen

We present the first dedicated observations of Interplanetary Scintillation (IPS) with the Murchison Widefield Array (MWA). We have developed a synthesis imaging technique, tailored to the properties of modern "large-N" low-frequency radio…

天体物理仪器与方法 · 物理学 2017-09-12 J . S. Morgan , J-P. Macquart , R. Ekers , R. Chhetri , M. Tokumaru , P. K. Manoharan , S. Tremblay , M. M. Bisi , B. V. Jackson

Around 10% of bright low-frequency radio sources observed with the Murchison Widefield Array (MWA) show strong Interplanetary Scintillation (IPS) on timescales of a few seconds, implying that almost all their low-frequency radio emission…

星系天体物理 · 物理学 2018-11-28 Elaine M. Sadler , Rajan Chhetri , John Morgan , Elizabeth K. Mahony , Thomas H. Jarrett , Steven Tingay

Advancements in VLBI instrumentation, driven by the geodetic community's goal of achieving positioning accuracy of 1 mm and stability of 0.1 mm/y, have led to the development of new broadband systems. Here, we assess the potential of these…

太阳与恒星天体物理 · 物理学 2025-04-23 A. Jaradat , G. Molera Calvés , J. Edwards , S. Ellingsen , T. McCarthy , J. Morgan

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…

天体物理仪器与方法 · 物理学 2023-01-04 John Morgan , Rajan Chhetri , Ron Ekers

We describe the parameters of a low-frequency all-sky survey of compact radio sources using Interplanetary Scintillation (IPS), undertaken with the Murchison Widefield Array (MWA). While this survey gives important complementary information…

星系天体物理 · 物理学 2019-02-08 J. S. Morgan , J-P. Macquart , R. Chhetri , R. D. Ekers , S. J. Tingay , E. M. Sadler

We determine the small-scale structure for a large sample of Compact Steep Spectrum (CSS) and Gigahertz Peaked Spectrum (GPS) sources and a sample of larger radio sources at 327 MHz using the technique of Inter-Planetary Scintillation (IPS)…

天体物理学 · 物理学 2007-05-23 S. Jeyakumar , D. J. Saikia , A. Pramesh Rao , V. Balasubramanian

We report on the first wide-field, very long baseline interferometry (VLBI) survey at 90 cm. The survey area consists of two overlapping 28 deg^2 fields centred on the quasar J0226+3421 and the gravitational lens B0218+357. A total of 618…

天体物理学 · 物理学 2009-11-13 Emil Lenc , Mike A. Garrett , Olaf Wucknitz , James M. Anderson , Steven J. Tingay

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…

宇宙学与河外天体物理 · 物理学 2014-12-01 J. Y. Koay , J. -P. Macquart

The VLBA was used at 1.6 GHz to observe a target field 50 arcminutes in diameter including the core of M31. Novel VLBI correlation techniques were used to observe 200 sources simultaneously, of which 16 were detected. We classify all 16 as…

We present results from a large global VLBI(Very Long Baseline Interferometry) survey of compact radio sources at 86 GHz which started in October 2001. The main goal of the survey is to increase the total number of objects accessible for…

天体物理学 · 物理学 2009-04-14 S. Lee , A. P. Lobanov , T. P. Krichbaum , A. Witzel , J. A. Zensus , M. Bremer , A. Greve , M. Grewing

Interplanetary scintillation observations of 48 of the 55 Augusto et al. (1998) flat spectrum radio sources were carried out at 111 MHz using the interplanetary scintillation method on the Large Phased Array (LPA) in Russia. Due to the…

天体物理学 · 物理学 2009-11-11 S. A. Tyul'bashev , A. Pedro

We present the data and analysis of VLBI observations at 1.6, 5 and 15 GHz of a sample of faint Gigahertz Peaked Spectrum (GPS) sources selected from the Westerbork Northern Sky Survey (WENSS). The 5 GHz observations involved a global array…

天体物理学 · 物理学 2016-08-30 Ignas Snellen , Richard Schilizzi , Huib-Jan van Langevelde

We present results from a large 86GHz global VLBI survey of compact radio sources. The main goal of the survey is to increase by factors of 3--5 the total number of objects accessible for future 3-mm VLBI imaging. The survey observations…

We present observations of high-amplitude rapid (2 s) variability toward two bright, compact extragalactic radio sources out of several hundred of the brightest radio sources in one of the 30x30 deg MWA Epoch of Reionization fields using…

We present preliminary results from a VLBI survey at $\lambda=6 $cm of a sample of 35 sources with flux densities of 2 - 100 mJy. These sources were selected from the VLA FIRST survey at $\lambda = 20 $cm, in a 3 degree field around the…

天体物理学 · 物理学 2009-10-31 S. T. Garrington , M. A. Garrett , A. Polatidis

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…

天体物理学 · 物理学 2009-11-11 B. Rickett , T. J. W. Lazio , F. D. Ghigo

(abridged) Very long baseline interferometry (VLBI) observations at 86$\,$GHz (wavelength, $\lambda = 3\,$mm) reach a resolution of about 50 $\mu$as, probing the collimation and acceleration regions of relativistic outflows in active…

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