A forming wide polar-ring galaxy at z ~ 0.05 in the VST Deep Field of the Fornax cluster^⋆

¹ INAF – Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131 Naples, Italy
e-mail: iodice@na.astro.it
² Dipartimento di Fisica, Universitá di Napoli “Federico II”, via Cintia 21, 80126 Naples, Italy
³ INAF – Osservatorio Astronomico di Teramo, via Maggini, 64100 Teramo, Italy

Received: 3 November 2014
Accepted: 21 November 2014

Abstract

We present the first deep photometry of what may be a good candidate for a forming polar-ring galaxy at redshift z ≃ 0.05. The object FCSS J033710.0-354727 is a background galaxy in the VST Deep Field of the Fornax cluster. The deep exposures combined with the high angular resolution of the OmegaCam at VST allowed us to carry out the first detailed photometric analysis for this system in the g and i bands to derive the galaxy structure and colors. Results show that the central object resembles a disk galaxy, surrounded by a ring-like structure that is twice as extended as the central disk. The warped geometry and bright knots observed along the polar direction, as well as some debris detected on the NW side with colors similar to those of the galaxy, suggest that the polar structure is still forming. We argue that the wide polar ring or disk is the result of the ongoing disruption of a companion galaxy in the potential well of the central object, which is two to three times more massive than the accreting galaxy.