The LOFAR LBA Sky Survey: Deep Fields

We present the first sub-mJy ($\approx0.7$ mJy beam$^{-1}$) survey to be completed below 100 MHz, which is over an order of magnitude deeper than previously achieved for widefield imaging any field at these low frequencies. The high resolution ($15 \times 15$ arcsec) image Bo\"otes 34-75 MHz made from 56 hours observation with LOw Frequency ARray (LOFAR) Low Band Antenna (LBA) system. observations and data reduction, including direction-dependent calibration, are described here. a radio source catalogue containing 1,948 sources detected area $23.6$ deg$^2$, peak flux density threshold $5\sigma$. Using existing datasets, we characterise astrometric uncertainties, finding positional uncertainty $\sim1.2$ arcsec scale about 5 per cent. available deep 144-MHz data, identified counterparts all 54-MHz sources, produced matched within optical coverage 829 sources. calculate Euclidean-normalised differential counts investigate low-frequency spectral indices between 54 144 both show general flattening in lower $\sim-0.75$ densities 100-1000 $\sim-0.5$ 5-10 mJy, due growing population star forming galaxies compact core-dominated AGN.