A 610-MHz survey of the ELAIS-N1 field with the Giant Metrewave Radio Telescope - observations, data analysis and source catalogue

Observations of the European Large-Area ISO Survey-North 1 (ELAIS-N1) field taken at 610 MHz with the Giant Metrewave Radio Telescope are presented. 19 pointings were observed, covering a total area of similar to 9 deg(2) with a resolution of 6 x 5 arcsec(2), position angle (PA) +45 degrees. Four of the pointings were deep observations with an rms of similar to 40 mu Jy before primary beam correction, with the remaining 15 pointings having an rms of similar to 70 mu Jy. 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 6 sigma. This work complements the large amount of optical and infrared data already available on the region. We calculate 610-MHz source counts down to 270 mu Jy, and find further evidence for the turnover in differential number counts below 1 mJy, previously seen at both 610 MHz and 1.4 GHz.