The Second VLBA Calibrator Survey: VCS2

Abstract

This paper presents an extension of the Very Long Baseline ArrayCalibrator Survey, called {VCS2,} containing 276 sources. This surveyfills in regions of the sky that were not completely covered by theprevious {VCS1} calibrator survey. The {VCS2} survey includes calibratorsources near the Galactic plane,-30deg{\textless}δ{\textless}-45deg, and {VLA} calibrators.The positions have been derived from astrometric analysis of the groupdelays measured at 2.3 and 8.4 {GHz} using the Goddard Space Flight Center{CALC/SOLVE} package. From the {VLBA} snapshot observations, images of thecalibrators are available, and each source is given a quality code foranticipated use. The {VCS2} catalog is available from the {NRAO} Web site.