18 days of MERLIN data and 42 hours of A-array VLA data at 1.4 GHz have been combined to image a 10 arcminute field centred on the Hubble Deep Field. This area includes both the Hubble Deep and Flanking Fields. A complete sample of 92 sources with flux densities above 40{mu}Jy have been detected using the VLA data, and imaged with the MERLIN+VLA combination at resolutions of 0.2, 0.3 and 0.5 arcsecond. These are the most sensitive 1.4 GHz images yet made, with rms noise levels of 3.3{mu}Jy/beam in the 0.2 arcsecond images. Virtually all the objects are resolved by the MERLIN+VLA combination images showing that they have angular sizes in the range 0.2 to 3 arcseconds, typically smaller than the sizes of the optical galaxy images. In addition to the imaging of 92 sources found with the VLA alone, the central 3 arcminutes, which encloses the HDF, has been separately imaged with the MERLIN+VLA combination at the full 3.3{mu}Jy/beam sensitivity to search for compact sources fainter than 40{mu}Jy. No additional sources were found that were not previously detected by the VLA, indicating that such sources are heavily resolved with MERLIN and hence must have typical angular sizes >0.5 arcseconds. In addition to the images, high quality astrometry is an equally important product of this work allowing reliable source identification in a crowded field. Radio sources associated with compact galaxies have been used to align both the HST WFPC2 frames and a CFHT optical field to the ICRF. The HST optical field has been aligned to better than 50 mas in the Deep Field itself, and to ~150 mas in the outer parts of the Flanking Fields. The proportion of starburst systems is found to increase with decreasing source strength. At fluxes below 100{mu}Jy in excess of 70% of the {mu}Jy sources are found to be starburst type systems associated with major disc galaxies in the redshift range 0.3 - 1.3. Some 40% of the brighter sources are found to be intermediate luminosity AGN systems identified with galxies in a similar redshift range. Around 85% of the sources are identified with galaxies brighter than I=25mag. The remaining 15% are associated with optically faint systems close to or beyond the HDF limit; many of these may be dust-shrouded starburst galaxies at high redshift (z>3). Approaching half the sources in the 10 arcminute field are detected in X-rays by the Chandra Satellite. The X-ray detection rate appears to be uncorrelated with the radio source classification.
Cone search capability for table B/avo.rad/catalog (MERLIN+VLA HFF/HDF(N) catalogue)
Cone search capability for table B/avo.rad/wsrt (WSRT data)
