GAMA-23 deep field with uGMRT Band-2: source catalogue and source count

Abstract

We present the low-frequency GAMA-23 field of the Galaxy and Mass Assembly (GAMA) survey with upgraded Giant Meterwave Radio Telescope (uGMRT) observations in Band-2 ($120-250$ MHz). The on-source observation was conducted for ${\sim}5$ hours. The final image achieved an off-source RMS noise of 320 $μ$Jy beam$^{-1}$, covering an area of $5.86\,\text{deg}^2$ with restoring beam size of $15.4''{\times}8.2''$ at the central frequency of 183 MHz. The catalogue derived from the radio image includes 569 sources with a flux density limit of ${\geq}\,5σ$. The flux density measurements and the positional accuracy are cross-verified and compared with other radio catalogues available in the literature. The spectral indices derived from fitting a power law are -0.68$^{+0.18}_{-0.23}$ for the ASKAP EMU catalogue and -0.72$^{+0.19}_{-0.24}$ for the NVSS catalogue. The normalised source count derived from this catalogue is consistent with models and observations with a nominal catalogue threshold of 1.7 mJy, while the sensitivity varies across the image.