325MHz GMRT survey of Herschel-ATLAS/GAMA fields

We describe a 325MHz survey, undertaken with the Giant Metrewave Radio Telescope (GMRT), which covers a large part of the three equatorial fields at 9, 12 and 14.5h of right ascension from the Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS) in the area also covered by the Galaxy And Mass Assembly (GAMA) survey. The full data set, after some observed pointings were removed during the data reduction process, comprises 212 GMRT pointings covering ~90deg^2^ of sky.

We have imaged and catalogued the data using a pipeline that automates the process of flagging, calibration, self-calibration and source detection for each of the survey pointings. The resulting images have resolutions of between 14 and 24-arcsec and minimum rms noise (away from bright sources) of ~1mJy/beam, and the catalogue contains 5263 sources brighter than 5{sigma}. We investigate the spectral indices of GMRT sources which are also detected at 1.4GHz and find them to agree broadly with previously published results; there is no evidence for any flattening of the radio spectral index below S_1.4_=10mJy.