The Survey of Centaurus A's Baryonic Structures (SCABS). I. Survey Description and Initial Source Catalogues

Abstract

We present new, wide-field, optical ($u'g'r'i'z'$) Dark Energy Camera observations covering $\sim21\,{\rm deg}^2$ centred on the nearby giant elliptical galaxy NGC5128 called "The Survey of Centaurus A's Baryonic Structures" (SCABS). The data reduction and analysis procedures are described including initial source detection, photometric and astrometric calibration, image stacking, and point-spread function modelling. We estimate 50 and 90 percent, field-dependent, point-source completeness limits of at least $u'=24.08$ and $23.62$ mag (AB), $g'=22.67$ and $22.27$ mag, $r'=22.46$ and $22.00$ mag, $i'=22.05$ and $21.63$ mag, and $z'=21.71$ and $21.34$ mag. Deeper imaging in the $u'$-, $i'$- and $z'$-bands provide the fainter limits for the inner $\sim3\,{\rm deg}^2$ of the survey, and we find very stable photometric sensitivity across the entire field of view. Source catalogues are released in all filters including spatial, photometric, and morphological information for a total of $\sim5\times10^5-1.5\times10^6$ detected sources (filter-dependent). We finish with a brief discussion of potential science applications for the data including, but not limited to, upcoming works by the SCABS team.