Gemini follow-up of two massive HI clouds discovered with the Australian Square Kilometer Array Pathfinder

Using the Gemini Multi Object Spectrograph (GMOS) we search for optical counterparts of two massive (∼109 M o) neutral hydrogen clouds near the spiral galaxy IC 5270, located in the outskirts of the IC 1459 group. These two H i clouds were recently discovered using the Australian Square Kilometer Array Pathfinder (ASKAP). Two low surface brightness optical counterparts to one of these H i clouds are identified in the new Gemini data that reaches down to magnitudes of ∼27.5 mag in the g-band. The observed H i mass-to-light ratio derived with these new data, MH I/Lg = 242, is among the highest reported to date. We are also able to rule out that the two H i clouds are dwarf companions of IC 5270. Tidal interactions and ram pressure stripping are plausible explanations for the physical origin of these two clouds.