scholarly journals 38. The cambridge survey of radio sources

1957 ◽  
Vol 4 ◽  
pp. 218-220 ◽  
Author(s):  
J. R. Shakeshaft
Keyword(s):  
Radio Telescope ◽  
Wave Length ◽  
Radio Sources ◽  
Polar Diagram ◽  
The North ◽  
Interference Fringes ◽  
Half Power ◽  
The Right ◽  
Right Ascension ◽  
East West

A survey of radio sources at a wave-length of 3·7 metres has been carried out with a large interferometric radio telescope (Ryle and Hewish, 1955) [1] which has a receiving area of about 5000 square metres. Four parabolic troughs are arranged at the corners of a rectangle 600 metres east–west by 50 metres north–south. The reception polar diagram of each, ± 1° by ± 7° to half-power points, is thus filled with interference fringes in the north–south plane as well as the east–west plane. Sources are observed at transit, the time of which gives the right ascension, while the declination is obtained by comparing the observed intensity on successive days as the phase of the north–south pattern is altered.

scholarly journals A Low frequency Southern Sky Survey Using the Mauritius Radio Telescope

2002 ◽  
Vol 199 ◽  
pp. 25-31
Author(s):  
N. Udaya Shankar
Keyword(s):  
Radio Telescope ◽  
Low Frequency ◽  
Fourier Synthesis ◽  
North East ◽  
The North ◽  
Sky Survey ◽  
Correlation Receiver ◽  
Complex Correlation ◽  
Right Ascension ◽  
East West

The Mauritius Radio Telescope (MRT) is a Fourier synthesis instrument which has been built to fill the gap in the availability of deep sky surveys at low radio frequencies in the southern hemisphere. It is situated in the north-east of Mauritius at a southern latitude of 20°.14 and an eastern longitude of 57°.73. The aim of the survey with the MRT is to contribute to the database of southern sky sources in the declination range −70° ≤ δ ≤ −10°, covering the entire 24 hours of right ascension, with a resolution of 4' × 4'.6sec(δ + 20.14°) and a point source sensitivity of 200 mJy (3σ level) at 151.5 MHz.MRT is a T-shaped non-coplanar array consisting of a 2048 m long East-West arm and a 880 m long South arm. In the East-West arm 1024 fixed helices are arranged in 32 groups and in the South arm 16 trolleys, with four helices on each, which move on a rail are used. A 512 channel, 2-bit 3-level complex correlation receiver is used to measure the visibility function. At least 60 days of observing are required for obtaining the visibilities up to the 880 m spacing. The calibrated visibilities are transformed taking care of the non-coplanarity of the array to produce an image of the area of the sky under observation.This paper will describe the telescope, the observations carried out so far, a few interesting aspects of imaging with this non-coplanar array and present results of a low resolution survey (13' × 18') covering roughly 12 hours of right ascension, and also present an image with a resolution of 4' × 4'.6sec(δ + 20.14°) made using the telescope.

scholarly journals 41. The spherical component of the galactic radio emission

1957 ◽  
Vol 4 ◽  
pp. 233-237
Author(s):  
J. E. Baldwin
Keyword(s):  
Radio Emission ◽  
Brightness Temperature ◽  
Radio Telescope ◽  
Galactic Plane ◽  
Wave Length ◽  
Spherical Component ◽  
Long Wave ◽  
Half Power ◽  
Right Ascension ◽  
Galactic Radio

As part of the programme of observations with the large Cambridge radio telescope, a survey of the integrated radio emission has been made using one of the four elements of the interferometer. At a wave-length of 3·7 metres this aerial has beam-widths to half-power points of 2° in right ascension and 15° in declination. The use of a long wave-length makes it possible to obtain accurate measurements of the brightness temperature of the sky in regions away from the galactic plane. It is with the radiation from these regions that this paper is primarily concerned.

scholarly journals The Central Component Of Centaurus A

1966 ◽  
Vol 19 (3) ◽  
pp. 421 ◽  
Keyword(s):  
Central Component ◽  
The South ◽  
Central Source ◽  
The North ◽  
North Eastern ◽  
The Right ◽  
Right Ascension ◽  
East West ◽  
Centaurus A

Transit observations of Centaurus A with a fan beam 1'�5 wide at 73 cm show that the north-eastern component of the central source has an east-west width of 1'�7 and that the south-western source has a width of 2'�3. Since the situation at 9�1 cm is roughly the reverse of this, the two components must have sharply different spectra. The right ascensions observed are 13h 22m 48s . 0 and 13h 22m 20s�2�os�2 (1950). The right ascension of the centre of NGC5128 has been separately determined as 13h 22m 31s�6�os�3, showing that the two components are at significantly unequal distances from the optical object.

scholarly journals Radio Emission from Clusters of Galaxies

1967 ◽  
Vol 20 (6) ◽  
pp. 715 ◽  
Author(s):  
HM Tovmassian ◽  
IG Moiseev
Keyword(s):  
Radio Emission ◽  
Radio Telescope ◽  
Radio Astronomy ◽  
Mathematical Expectation ◽  
Astronomical Observatory ◽  
Radio Sources ◽  
Clusters Of Galaxies ◽  
Astronomy Observatory ◽  
Group 5 ◽  
East West

From Abell's (1958) list of clusters of galaxies, 137 clusters of distance group 5 were observed at 1410 MHz with the 210 ft radio telescope of the Australian National Radio Astronomy Observatory at Parkes. The detected radio sources were further confirmed hy observations at 2650 MHz with the same telescope and at 408 MHz with the east-west arm of the Mills Cross at the Molonglo Radio Astronomical Observatory. A total of 25 radio sources was detected within 5' arc of the centres of corresponding clusters of galaxies, while the mathematical expectation of the number of random coincidences with clusters is about two or three

Observations of Galactic HII Regions with the Fleurs Synthesis Telescope

1978 ◽  
Vol 3 (4) ◽  
pp. 278-279 ◽  
Author(s):  
D. S. Retallack
Keyword(s):  
Hii Regions ◽  
Standard Process ◽  
The North ◽  
The Cross ◽  
Half Power ◽  
East West

The Fleurs Synthesis Telescope (FST) has been used to map a number of bright, southern galactic HII regions at 1415 MHz. Descriptions of the FST can be found in Christiansen (1973) and associated papers. For the observations reported here, both the east-west and the north-south arms of the cross were used resulting in beamshapes which are nearly circular with half-power widths of 50” arc. The maps have been “cleaned” using a standard process (Högbom 1974).

The Application of Radio Interferometers in Astrometry

1975 ◽  
Vol 26 ◽  
pp. 453-456
Author(s):  
S. Gorgolewski
Keyword(s):  
Radio Telescope ◽  
High Accuracy ◽  
Precision Measurements ◽  
Radio Sources ◽  
Right Ascension

AbstractAn account is given of the recent precision measurements of position of radio sources by VLBI and especially phase-stable interferometer systems of the 5 km radio telescope in Cambridge.A brief description of the 5 km. telescope is given as well as some of the remarkably accurate determinations of declination and right ascension of radio sources related to the PK4 catalogue. The monitoring of UT1 with high accuracy has also been achieved with the 5 km telescope.Some prospects of even better accuracies with phase-stable interferometers – and VLBI techniques are also presented.

scholarly journals Observations of the bright radio sources in the North Celestial Pole region at the RATAN-600 radio telescope

2001 ◽  
Vol 370 (1) ◽  
pp. 78-86 ◽  
Author(s):  
M. G. Mingaliev ◽  
V. A. Stolyarov ◽  
R. D. Davies ◽  
S. J. Melhuish ◽  
N. A. Bursov ◽  
...  
Keyword(s):  
Radio Telescope ◽  
Radio Sources ◽  
The North ◽  
Celestial Pole

scholarly journals Studies of radio sources at 159 Mc/s

1959 ◽  
Vol 9 ◽  
pp. 487-491 ◽  
Author(s):  
S. Archer ◽  
J. E. Baldwin ◽  
D. O. Edge ◽  
B. Elsmore ◽  
P. A. G. Scheuer ◽  
...  
Keyword(s):  
Large Diameter ◽  
Small Diameter ◽  
Resolving Power ◽  
Radio Sources ◽  
The South ◽  
The West ◽  
Phase Switching ◽  
The North ◽  
Interference Fringes ◽  
Angular Diameters

Two years ago the Cambridge 4-aerial interferometer [1] was adapted to work at a frequency of 159 Mc/s, the resolving power thereby being increased by a factor of four over that at the previous frequency, 81.5 Mc/s. The overall beamwidth at 159 Mc/s is 1.2 degrees by 7 degrees but the beam contains interference fringes in two planes at right angles, so that, by phase-switching between the east pair and the west pair of aerials, sources with angular diameters greater than about 7 minutes of arc are eliminated. A survey using this technique has been carried out by Edge and Shakeshaft and may be called a “small diameter” survey. If the phase-switching receiver is connected between the north pair and the south pair of aerials it is possible to record sources with diameters up to about 1 degree and to measure diameters between 2 and 8 minutes of arc. Archer and Baldwin have used the aerial in this way to make a “large diameter” survey. These two surveys will be referred to collectively as the 3C survey.

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