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

ABSTRACT Observations of the ELAIS-N1 field taken at 610 MHz with the Giant Metrewave Radio Tele-scope are presented. Nineteen pointings were observed, covering a total area of ∼9 deg 2 witha resolution of 6 × 5 arcsec 2 , PA +45 ◦ . Four of the pointings were deep observations with anrms of ∼40 µJy before primary beam correction, with the remaining fiftee n pointings havingan rms of ∼ 70 µJy. The techniques used for data reduction and production of a mosaickedimage of the region are described, and the final mosaic is pres ented, along with a catalogueof 2500 sources detected above 6σ. This work complements the large amount of optical andinfrared data already available on the region. We calculate 610-MHz source counts down to270 µJy, and find further evidence for the turnoverin differentia l number counts below 1 mJy,previously seen at both 610 MHz and 1.4 GHz.Key words: surveys – catalogues – radio continuum: galaxies 1 INTRODUCTIONThe Spitzer Wide-area Infrared Extragalactic (SWIRE;Lonsdale et al. 2003) survey has the largest sky coverage ofthe legacy surveys being performed by the Spitzer Space Telescope(Werner et al. 2004). A total area of ∼49 deg

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