中文
相关论文

相关论文: Potential Targets for ASTRO-G In-Beam Phase-Refere…

200 篇论文

We have conducted a deep, very long baseline interferometry (VLBI) observation at 1.4 GHz of an area of sky located within the NOAO Bootes field, using the NRAO VLBA and 100-m Green Bank Telescope. Applying wide-field VLBI techniques, a…

天体物理学 · 物理学 2009-11-10 M. A. Garrett , J. M. Wrobel , R. Morganti

We report on an ongoing effort to image active galactic nuclei simultaneously observed at 2.3 and 8.6 GHz in the framework of a long-term VLBI project RDV (Research and Development - VLBA) started in 1994 aiming to observe compact…

天体物理学 · 物理学 2008-12-31 A. B. Pushkarev , Y. Y. Kovalev

We present Very Large Array observations at 1.4 and 5 GHz of a sample of 16 quasi-stellar objects (QSOs) at z = 1.78 to 2.71. Half of the chosen quasars are bright at mm wavelengths (250 or 350 GHz) while the other half were not detected at…

天体物理学 · 物理学 2008-11-26 A. Petric , C. L. Carilli , F. Bertoldi , A. Beelen , P. Cox , A. Omont

We present a study of the radio variability of bright, $S_{1.4}\geq100$ mJy, high-redshift quasars at $z\geq3$ on timescales up to 30-40 years. The study involved simultaneous RATAN-600 measurements at frequencies of 2.3, 4.7, 8.2, 11.2,…

We present very long baseline interferometry (VLBI) images of ten very high redshift (z>3) quasars at 5 GHz. The sources 0004+139, 0830+101, 0906+041, 0938+119 and 1500+045 were observed in September 1992 using a global VLBI array, while…

The quasar B2005+403 located behind the Cygnus region, is a suitable object for studying the interplay between propagation effects, which are extrinsic to the source and source intrinsic variability. On the basis of VLBI experiments…

天体物理学 · 物理学 2013-09-26 K. E. Gabanyi , T. P. Krichbaum , S. Britzen , U. Bach , E. Ros , A. Witzel , J. A. Zensus

We present the description and early results of the mJy Imaging VLBA Exploration at 20 cm (mJIVE-20). mJIVE-20 is a large project on the Very Long Baseline Array which uses "filler" time to systematically inspect a large sample of mJy radio…

宇宙学与河外天体物理 · 物理学 2015-06-17 A. T. Deller , E. Middelberg

We present basic observational data on the 6C** sample. This is a new sample of radio sources drawn from the 151 MHz 6C survey, which was filtered with radio criteria chosen to optimize the chances of finding radio galaxies at z > 4. The…

We observed 20 Palomar-Green (PG) quasars at low redshift ($z<0.5$) with total flux density > 1 mJy, including 4 radio-loud quasars (RLQs) and 16 radio-quiet quasars (RQQs), using the Very Long Baseline Array (VLBA) at 5 GHz. Ten RQQs are…

星系天体物理 · 物理学 2022-11-01 Ailing Wang , Tao An , Xiaopeng Cheng , Luis C. Ho , Kenneth I. Kellermann , Willem A. Baan , Jun Yang , Yingkang Zhang

We present the results from two radio integrations at 8.4 GHz using the VLA. One of the fields, at 13h,+43d (SA13 field), has an rms noise level of 1.49 microJy and is the deepest radio image yet made. Thirty-four sources in a complete…

天体物理学 · 物理学 2009-11-07 E. B. Fomalont , K. I. Kellermann , R. B. Partridge , R. A. Windhorst , E. A. Richards

We describe a survey in the ELAIS N2 region with the VLA at 43.4 GHz, carried out with 1627 independent snapshot observations in D-configuration and covering about 0.5 square degrees. One certain source is detected, a previously-catalogued…

宇宙学与河外天体物理 · 物理学 2015-05-19 Jasper Wall , Rick Perley , Robert Laing , Sean Stotyn , Angela Taylor , Joe Silk

Millimetre-VLBI is an important tool in AGN astrophysics, but it is limited by short atmospheric coherence times and poor receiver and antenna performance. We demonstrate a new kind of phase referencing for the VLBA, enabling us to increase…

天体物理学 · 物理学 2007-05-23 E. Middelberg , A. L. Roy , R. C. Walker , H. Falcke , T. P. Krichbaum

We performed observations with the Effelsberg 100-m radio telescope to measure flux densities and polarised emission of sources selected from the "Deep X-ray Radio Blazar Survey" (DXRBS) to better define their spectral index behaviour in…

宇宙学与河外天体物理 · 物理学 2011-07-28 Franco Mantovani , Marco Bondi , Karl-Heinz Mack

We give a progress report on a snapshot 86 GHz-VLBI survey of the EGRET blazars with the observatories of the CMVA. A high fraction (17/18) of the EGRET blazars were detected on the Pico Veleta-Onsala baseline with a baseline length on the…

天体物理学 · 物理学 2016-08-30 Geoffrey C. Bower

We present 1.4 and 5 GHz observations taken with the Very Large Array (VLA), and observations at 250 GHz obtained with the Max-Planck millimeter bolometer (MAMBO) at the IRAM 30~m telescope, of ten optically selected Quasi-stellar Objects…

Despite the plethora of deep (sub-mJy) radio surveys there remains considerable doubt as to the exact nature of the galaxies contributing to the source counts. Current evidence suggests that starformation in moderately luminous 'normal'…

天体物理学 · 物理学 2009-11-11 Nick Seymour , Derek Moss , Ian McHardy , Katherine Gunn , Mat Page , Nic Loaring , Tom Dwelly

We present multiwaveband observations of a well selected sample of 28 quasars and two radio galaxies with flat radio spectra and strong millimeter wave emission (referred to here as FSRQ's). The observations include multifrequency VLBI…

天体物理学 · 物理学 2009-10-31 S. D. Bloom , A. P. Marscher , E. M. Moore , W. K. Gear , H. Terasranta , E. Valtaoja , H. D. Aller , M. F. Aller

We present the first wide area (19 deg$^2$), deep ($\approx120-150$ {\mu}Jy beam$^{-1}$), high resolution ($5.6 \times 7.4$ arcsec) LOFAR High Band Antenna image of the Bo\"otes field made at 130-169 MHz. This image is at least an order of…

We present results of a pilot observational wide-field VLBI campaign on probing scattering properties of the partly ionized interstellar medium towards the Galactic plane sky region between $28^\circ<l<36^\circ$ and $|b|<1^\circ$. This…

We present deep L-Band observations of the equatorial field centered on the z=6.3 SDSS QSO, reaching a 1 sigma sensitivity of ~2.5 uJy at the center of the field. We extracted a catalog of 1489 radio sources down to a flux density of ~12.5…