Discovery of 178 Giant Radio Galaxies in 1059 deg$^2$ of the Rapid ASKAP Continuum Survey at 888 MHz

We report the results of a visual inspection of images of the Rapid ASKAP Continuum Survey (RACS) in search of extended radio galaxies (ERG) that reach or exceed linear sizes on the order of one Megaparsec. We searched a contiguous area of 1059deg$^2$ from RA$_{\rm J}$=20$^h$20$^m$ to 06$^h$20$^m$, and $-50^{\circ} $1Mpc, of which 18 exceed 2Mpc and the largest one is 3.4Mpc. Their redshifts range from 0.02 to $\sim$2.0, but only 10 of the 178 new GRS have spectroscopic redshifts. For the 146 host galaxies the median $r$-band magnitude and redshift are 20.9 and 0.64, while for the 32 quasars or candidates these are 19.7 and 0.75. Merging the six most recent large compilations of GRS results in 458 GRS larger than 1Mpc, so we were able to increase this number by $\sim39\%$ to now 636.