出版社:SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要:We report on a recent 90-cm wide-field VLBI survey of two 3.1-deg2 fields using the VLBA,
Westerbork and Jodrell Bank telescopes. In-beam calibration was used to calibrate each field; this
process was simplified by imaging the calibrators in DIFMAP and transferring the calibration
solutions to AIPS using the newly developed DIFMAP task cordump. We detected and imaged
13 out of the 141 sources originally detected by the low resolution (54′′) WENSS survey of the
same two fields. The sources were detected at 7−12 sigma levels above the image noise, had total
flux densities in the range of 85−1640 mJy and were located between 16′ and 58′ from the phase
centre of each field. This is the first systematic (and non-biased), deep, high-resolution survey of
the low-frequency radio sky. These initial results suggest that new instruments such as LOFAR
should detect many compact radio sources and that plans to extend these arrays to baselines of
several thousand kilometres are warranted.