A New Cartwheel-like Collisional Ring Galaxy
A New Cartwheel-like Collisional Ring Galaxy
Vladimir P. Reshetnikov, Sergey S. Savchenko, Alexander A. Marchuk, Ilia V. Chugunov, Matvey D. Kozlov, Dmitry I. Makarov, Aleksandra V. Antipova, Anastasia M. Sypkova
AbstractWe report the discovery of a new Cartwheel-type collisional ring galaxy, PGC\,1112751, which we named ``Eridanus Wheel'' (EW). Such systems result from head-on collisions between galaxies and are of considerable interest as laboratories for studying star formation in propagating density waves and the response of the star-gas disk of galaxies to strong external perturbations. During a systematic visual inspection of fields from the DESI Legacy Imaging Surveys, we identified a galaxy at a redshift of $z=0.0856$ whose morphology closely resembles that of the famous Cartwheel Galaxy. EW exhibits a well-defined inner ring and a more diffuse outer ring, with so-called ``spokes'' visible in the region between them. The ring galaxy and its possible intruder are connected by a faint optical bridge. The projected distance between the centers of the galaxies is about 60 kpc. Using data from the DESI Legacy Surveys, we performed a photometric study of galaxies in the $griz$ filters. We conclude that the Eridanus Wheel is a giant late-type galaxy with a strong radial color gradient, whose observed morphology is most likely explained by a relatively recent head-on collision with an early-type galaxy. The further evolution of this object will most likely lead to the formation of a galaxy with a low surface brightness disk.