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Date and Time of the Query: 2019-05-25 T02:42:56 PDT
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For refcode 2001PASP..113..362C:
Retrieve 3399 NED objects in this reference.
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Copyright by Astronomical Society of the Pacific. Reproduced by permission
2001PASP..113..362C Offset Pointing Calibrators for Large Radio Telescopes J. J. CONDON AND Q. F. YIN National Radio Astronomy Observatory,1 520 Edgemont Road, Charlottesville, VA 22903; jcondon@nrao.edu, qyin@nrao.edu Received 2000 November 8; accepted 2000 November 28 ABSTRACT. We present a catalog of pointing calibrators suitable for offset pointing and for determining the pointing constants of large radio telescopes. It contains 3399 strong, compact, and unconfused radio sources with accurate ({sigma}_{alpha}_ cos {delta} ~ {sigma}_{delta} ~ 0.5") positions from the NRAO Very Large Array Sky Survey (NVSS) uniformly covering the sky north of J2000 {delta} = -40^deg^. The NVSS images, restored with a {theta} = 45" FWHM Gaussian beam, were also convolved to larger beam sizes {theta} = 90", 180", 360", 540", and 720". The catalog lists the maximum beam size {theta}_m_ for which each calibration source remains unconfused and a single Gaussian fit yields an rms position error {sigma} <= {theta}_m_/100. For all {delta} > -40^deg^, the average angular distance to the nearest calibrator is only <{phi}> ~ 0.03 rad, so offset pointing from these calibrators may reduce slowly varying pointing errors (caused by incorrect values for the traditional pointing constants, gravitational deformations, differential thermal expansion, refraction, etc.) by factors up to <{phi}>^-1^ ~ 30.
Retrieve 3399 NED objects in this reference.
Please click here for ADS abstract

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