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

TL;DR

This paper presents a detailed 610-MHz survey of the ELAIS-N1 field using the GMRT, including observations, data processing, and a source catalogue, revealing source counts and their distribution.

Contribution

It provides the first extensive 610-MHz survey of ELAIS-N1 with a large source catalogue and analysis of source counts, enhancing multi-wavelength data integration.

Findings

Detected 2500 sources above 6 sigma threshold.

Measured source counts down to 270 microJy.

Confirmed the turnover in differential number counts below 1 mJy.

Abstract

Observations of the ELAIS-N1 field taken at 610 MHz with the Giant Metrewave Radio Telescope are presented. Nineteen pointings were observed, covering a total area of 9 square degrees with a resolution of 6" x 5", PA +45 deg. Four of the pointings were deep observations with an rms of 40 microJy before primary beam correction, with the remaining fifteen pointings having an rms of 70 microJy. 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 microJy, and find further evidence for the turnover in differential number counts below 1 mJy, previously seen at both 610 MHz and 1.4 GHz.