Deep 3-GHz observations of the Lockman Hole North with the Very Large Array – II. Catalogue and μJy source properties

• Published in: Monthly notices of the Royal Astronomical Society 2016-11, Vol.462 (3), p.2934-2949
• Main Authors: Vernstrom, T., Scott, Douglas, Wall, J. V., Condon, J. J., Cotton, W. D., Kellermann, K. I., Perley, R. A.
• Format: Article
• Language: English
• Subjects: Active galactic nuclei; Arrays; Catalogues; Counting; Estimates; Infrared; Spectra; X-rays
• ISSN: 0035-8711; 1365-2966
• DOI: 10.1093/mnras/stw1836

This is the second of two papers describing the observations and source catalogues derived from sensitive 3-GHz images of the Lockman Hole North using the Karl G. Jansky Very Large Array (VLA). We describe the reduction and cataloguing process, which yielded an image with 8 arcsec resolution and instrumental noise of σn = 1.01 μJy beam−1 rms (before primary-beam corrections) and a catalogue of 558 sources detected above 5σn. We include details of how we estimate source spectral indices across the 2-GHz VLA bandwidth, finding a median index of −0.76 ± 0.04. Stacking of source spectra reveals a flattening of spectral index with decreasing flux density. We present a source count derived from the catalogue. We show a traditional count estimate compared with a completely independent estimate made via a P(D) confusion analysis, and find very good agreement. Cross-matches of the catalogue with X-ray, optical, infrared, radio, and redshift catalogues are also presented. The X-ray, optical and infrared data, as well as active galactic nuclei (AGN) selection criteria allow us to classify 10 per cent as radio-loud AGN, 28 per cent as radio-quiet AGN, and 58 per cent as star-forming galaxies, with only 4 per cent unclassified.