The VLA-COSMOS 3 GHz Large Project: Continuum data and source catalog
  release
  We present the VLA-COSMOS 3 GHz Large Project based on 384 hours of
observations with the Karl G. Jansky Very Large Array (VLA) at 3 GHz (10 cm)
toward the two square degree Cosmic Evolution Survey (COSMOS) field. The final
mosaic reaches a median rms of 2.3 uJy/beam over the two square degrees at an
angular resolution of 0.75". To fully account for the spectral shape and
resolution variations across the broad (2 GHz) band, we image all data with a
multiscale, multifrequency synthesis algorithm. We present a catalog of 10,830
radio sources down to 5 sigma, out of which 67 are combined from multiple
components. Comparing the positions of our 3 GHz sources with those from the
Very Long Baseline Array (VLBA)-COSMOS survey, we estimate that the astrometry
is accurate to 0.01" at the bright end (signal-to-noise ratio, S/N_3GHz > 20).
Survival analysis on our data combined with the VLA-COSMOS 1.4~GHz Joint
Project catalog yields an expected median radio spectral index of alpha=-0.7.
We compute completeness corrections via Monte Carlo simulations to derive the
corrected 3 GHz source counts. Our counts are in agreement with previously
derived 3 GHz counts based on single-pointing (0.087 square degrees) VLA data.
In summary, the VLA-COSMOS 3 GHz Large Project simultaneously provides the
largest and deepest radio continuum survey at high (0.75") angular resolution
to date, bridging the gap between last-generation and next-generation surveys.
