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 ~ 9 deg² with a resolution of 6 × 5 arcsec², position angle (PA) +45°. Four of the pointings were deep observations with an rms of ~40 μJy before primary beam correction, with the remaining 15 pointings having an rms of ~70 μJy. 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 270 μJy, and find further evidence for the turnover in differential number counts below 1 mJy, previously seen at both 610 MHz and 1.4 GHz.