SIMBAD references

Observations of the European Large-Area ISO Survey-North 1 (ELAIS-N1) field taken at 610MHz with the Giant Metrewave Radio Telescope are presented. 19 pointings were observed, covering a total area of ∼ 9deg² with a resolution of 6x5arcsec², position angle (PA) +45°. Four of the pointings were deep observations with an rms of ∼40µJy before primary beam correction, with the remaining 15 pointings having an rms of ∼70µJy. The techniques used for data reduction and production of a mosaicked image of the region are described, and the final mosaic is presented, along with a catalogue of 2500 sources detected above 6σ. This work complements the large amount of optical and infrared data already available on the region. We calculate 610-MHz source counts down to 270µJy, and find further evidence for the turnover in differential number counts below 1mJy, previously seen at both 610MHz and 1.4GHz.