A new photometric investigation of the double-ringed galaxy ESO 474−G26: unveiling the formation scenario

We present a detailed photometric study of the peculiar double-ringed galaxy ESO 474-G26. Near-infrared (NIR) and optical data have been used, with the main goal of constraining the formation history of ESO 474-G26. NIR photometry is fundamental in this kind of study, because it gives better constraints on the spectral energy distribution (SED) and traces the older stellar population of the galaxy well. This galaxy presents a very complex structure with two almost orthogonal rings, one in the equatorial and another in the polar plane, around an elliptical-like object. Due to the peculiar morphology of ESO 474-G26, we used both NIR images (J and K bands) to derive accurate analysis of the stellar light distribution and optical images (in the B, V and R bands) to derive colour profiles and colour maps to study the structure of the rings. The observational characteristics of ESO 474-G26 are typical of galaxies that have experienced some kind of interaction during their evolution. We investigated two alternatives: a merging process and an accretion event.