11 Result(s)

Article

Electronic Multi-beam Radio Astronomy Concept: Embrace a Demonstrator for the European SKA Program

ASTRON has demonstrated the capabilities of a 4 m², dense phased array antenna (Bij de Vaate et al., 2002) for radio astronomy, as part of the Thousand Element Array project (ThEA). Although it proved the princip...

A. Van Ardenne, P. N. Wilkinson, P. D. Patel, J. G. Bij De Vaate in Experimental Astronomy (2004)

Article

A disrupted radio jet inside the host galaxy of the quasar 3C48

THE nearby quasar 3C48 was the first to be optically identified¹, and its redshift, z = 0.368 (ref. 2), was the second, after that of 3C273³, to be determined. Despite this pedigree, its detailed radio structure ...

P. N. Wilkinson, A. K. Tzioumis, J. M. Benson, R. C. Walker, R. S. Simon… in Nature (1991)

Article

Space missions: Very-long-baseline interferometry takes to the sky

P.N. Wilkinson in Nature (1984)

Article

Peculiar radio structure in the quasar 3C380

The majority of powerful extragalactic radio sources have steep radio spectra and angular sizes >5 arc s. Their basically symmetrical double structures can be explained by means of two, originally antiparallel...

P. N. Wilkinson, R. S. Booth, T. J. Cornwell, R. R. Clark in Nature (1984)

Article

Low-frequency variability and predicted superluminal motion in 3C147

VLBI observations of 3C147 reveal that its core is a low-frequency variable radio source which has brightened by a factor of 2 in 6 years. In combination with X-ray observations, this implies that bulk relativ...

R. S. Simon, A. C. S. Readhead, A. T. Moffet, P. N. Wilkinson, B. Allen… in Nature (1983)

Article

VLBI structures of the images of the double QSO 0957 + 561

Very long baseline interferometry (VLBI) observations of the double QSO 0957 + 561 have revealed radio fine structure in the two ‘image’ components A and B. The structures are similar, both of the ‘core–jet’ t...

R. W. Porcas, R. S. Booth, I. W. A. Browne, D. Walsh, P. N. Wilkinson in Nature (1981)

Article

VLBI Observations of the double QSO, 0957 + 561 A, B

Walsh et al.¹ originally suggested that the double QSO 0957 + 561 A, B might be images of the same object formed by a gravitational lens because of their remarkably similar optical spectra. Additional optical spe...

R. W. Porcas, R. S. Booth, I. W. A. Browne, D. Walsh, P. N. Wilkinson in Nature (1979)

Article

Bent beams and the overall size of extragalactic radio sources

In a small sample of extragalactic radio sources, curvature is found to be a common feature in bright radio components coincident with quasi-stellar objects. In 3C273 and 3C345 the curvature is smooth between ...

A. C. S. Readhead, M. H. Cohen, T. J. Pearson, P. N. Wilkinson in Nature (1978)

Article

Radio structure of 3C147 determined by multi-element very long baseline interferometry

We have determined the radio structure of the quasar 3C147 from multi-baseline VLBI data at 609 MHz using both a conventional method and a technique which uses the ‘closure’ phase information to produce a good...

P. N. Wilkinson, A. C. S. Readhead, G. H. Purcell, B. Anderson in Nature (1977)

Article

Radio structure of the M87 jet

THE central region of M87 has a complex radio structure. There are at least three components^1,2, with diameters ≈0″.0013, ≈0″.01 and ≈0″.3, coincident with the optical nucleus of the galaxy and on either side the...

P. N. WILKINSON in Nature (1974)

Article

Radio structure of the ‘double quasar’ 4C11.50

WAMPLER et al.¹ have recently announced the discovery of a close pair of optical quasars associated with the radio source 4C11.50. The brighter quasar (a) has a redshift of 0.436, whereas its companion (b), 4.8 a...

D. STANNARD, P. N. WILKINSON, R. S. WARWICK, R. J. DAVIS in Nature (1974)