Deep 3-GHz observations of the Lockman Hole North with the Very Large Array - II. Catalogue and μJy source properties
Abstract
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.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- November 2016
- DOI:
- 10.1093/mnras/stw1836
- arXiv:
- arXiv:1603.03085
- Bibcode:
- 2016MNRAS.462.2934V
- Keywords:
-
- methods: data analysis;
- surveys;
- cosmology: observations;
- radio continuum: galaxies;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 16 pages, 7 tables, 14 figures. Accepted by MNRAS. Catalogues available online from MNRAS and vizier database once published