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相关论文: A suspected Dark Lens revealed with the e-EVN

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So far the lens J1131-1231 has been studied only at optical and X-ray wavelengths. A detection in the radio was almost missed as a result of an incorrect position and archive problems. A direct analysis of NVSS uv data - in contrast to the…

天体物理学 · 物理学 2008-11-24 Olaf Wucknitz , Filomena Volino

Context: There is a possibility that the optically unidentified radio source J1218+2953 may act as a gravitational lens, producing an optical arc ~4" away from the radio position. Until now, the nature of the lensing object has been…

宇宙学与河外天体物理 · 物理学 2010-05-05 S. Frey , Z. Paragi , R. M. Campbell , A. Moor

A single-screen model of the gravitational lens system 2016+112 is proposed, that explains recent Hubble Space Telescope} (HST) infrared (NICMOS-F160W) observations and new high-resolution European VLBI Network (EVN) 5-GHz radio…

天体物理学 · 物理学 2009-11-06 L. V. E. Koopmans , M. A. Garrett , R. D. Blandford , C. R. Lawrence , A. R. Patnaik , R. W. Porcas

Gravitational lensing is a powerful tool for quantifying the mass content and distribution in distant galaxies. By using milliarcsecond angular resolution observations of radio-loud gravitationally lensed sources it is also possible to…

星系天体物理 · 物理学 2019-02-20 C. Spingola , J. P. McKean , A. Deller , J. Moldon

Studying transient phenomena with the Very Long Baseline Interferometry (VLBI) technique faces severe difficulties because the turnaround time of the experiments from the observations to the scientific result is rather long. The e-VLBI…

天体物理学 · 物理学 2007-05-23 Z. Paragi , M. A. Garrett , B. Paczynski , C. Kouveliotou , A. Szomoru , C. Reynolds , S. M. Parsley , T. Ghosh

The European VLBI Network (EVN) is in the process of establishing an e-VLBI array in which the radio telescopes and the EVN correlator at JIVE are connected in real-time, via high-speed national fibre optic networks and the pan-European…

天体物理学 · 物理学 2007-05-23 M. A. Garrett

Submillimetre-selected galaxies (SMGs) at high redshift ($z$ $\sim$ 2) are potential host galaxies of active galactic nuclei (AGN). If the local Universe is a good guide, $\sim$ 50$\%$ of the obscured AGN amongst the SMG population could be…

Some microquasars are permanently bright radio sources while others are faint but produce powerful radio outbursts. Most of the X-ray binaries (XRB) however are very faint or undetected in the radio regime. The European VLBI Network (EVN)…

天体物理学 · 物理学 2007-05-23 Zsolt Paragi , Michael A. Garrett , Andrew D. Biggs

Measurements of the properties of gravitational lenses have the power to tell us what sort of universe we live in. The brightest known radio Einstein ring/gravitational lens PKS 1830-211 (Jauncey et al., 1991), whilst obscured by our Galaxy…

We present evidence that the optically unidentified radio source, FIRST J121839.7+295325, may be strongly lensing a background galaxy. We estimate the redshift of the assumed gravitational arc, discovered in parallel imaging with HST, from…

天体物理学 · 物理学 2009-11-13 R. E. Ryan , S. H. Cohen , R. A. Windhorst , C. R. Keeton , T. J. Veach

Very Long Baseline Interferometry (VLBI) offers unrivalled resolution in studies of celestial radio sources. The subjects of interest of the IAU Symposium No. 356, the Active Galactic Nuclei (AGN) of all types, constitute the major…

天体物理仪器与方法 · 物理学 2021-02-03 Leonid I. Gurvits , Robert Beswick , Melvin Hoare , Ann Njeri , Jay Blanchard , Carla Sharpe , Adrian Tiplady , Aletha de Witt

Less than $200$ radio-loud active galactic nuclei (AGN) are known above redshift $4$. Around $40$ of them have been observed at milliarcsecond (mas) scale resolution with very long baseline interferometry (VLBI) technique. Some of them are…

I review observational properties of low power radio loud AGN. High resolution VLBI observations allow the estimate of the jet velocity and orientation with respect to the line of sight and the determination of the Doppler factor. These…

天体物理学 · 物理学 2009-04-14 G. Giovannini , M. Giroletti

The European VLBI Network (EVN) has been used at two epochs in 2003 and 2009 to obtain multi-frequency high-resolution images of the merger galaxy NGC6240 in order to study the radio properties of all compact high-brightness components in…

宇宙学与河外天体物理 · 物理学 2015-05-28 Y. Hagiwara , W. A. Baan , H. -R. Kloeckner

VLBI at millimeter wavelengths (mm-VLBI) allows the detailed imaging of compact galactic and extragalactic radio sources with micro-arcsecond scale resolution, unaccessible by other observing techniques. Here we discuss the scientific…

天体物理学 · 物理学 2007-05-23 T. P Krichbaum , A. Witzel , J. A. Zensus

VLBI now has the capability of imaging relatively large fields-of-view (~ 5 arcmin sq) with sub-mJy detection limits. In principle such observations can distinguish between starburst and AGN activity in cosmologically distant sources. We…

天体物理学 · 物理学 2009-11-06 M. A. Garrett , T. W. B. Muxlow , S. T. Garrington

We use a Chandra X-ray observation of the gravitationally lensed system MGB2016+112 at z=3.273 to elucidate presence of at least two X-ray sources. We find that these sources are consistent with the VLBI components measured by…

高能天体物理现象 · 物理学 2021-08-25 Daniel Schwartz , Cristiana Spingola , Anna Barnacka

The gravitational lens system CLASS B2108+213 has two lensed images separated by 4.56 arcsec. Such a wide image separation suggests that the lens is either a massive galaxy, or is composed of a group of galaxies. To investigate the…

天体物理学 · 物理学 2009-11-13 A. More , J. P. McKean , T. W. B. Muxlow , R. W. Porcas , C. D. Fassnacht , L. V. E. Koopmans

We present a novel pilot search for gravitational lenses in the mJIVE-20 survey, which observed $24\,903$ radio sources selected from FIRST with the VLBA at an angular resolution of 5 mas. We have taken the visibility data for an initial…

星系天体物理 · 物理学 2018-12-19 C. Spingola , J. P. McKean , M. Lee , A. Deller , J. Moldon

Radio-loud active galactic nuclei (AGN) with their jets pointed close to our line of sight constitute the majority of extragalactic $\gamma$-ray sources and significantly contribute to the radiation observed in the even higher energy…

高能天体物理现象 · 物理学 2025-02-06 J. Kőmíves , K. É. Gabányi , S. Frey , Z. Paragi , T. An , E. Kun
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