A large-scale neutral hydrogen (H i) ring serendipitously found in the Leo I galaxy group is 200 kpc in diameter with MHi ~ 1:67 X 109M⊙, unique in size in the Local Universe. It is still under debate where this Hi ring originated - whether it has formed out of the gas remaining after the formation of a galaxy group (primordial origin) or been stripped during galaxy-galaxy interactions (tidal origin). We are investigating the optical and Hi gas properties of the dwarf galaxies located within the gas ring in order to probe its formation mechanism. In this work, we present the photometric properties of the dwarfs inside the ring using the CFHT MegaCam u*, g', r' and i'-band data. We discuss the origin of the gas ring based on the stellar age and metal abundance of dwarf galaxies contained within it.

ABSTRACT
1. INTRODUCTION
2. OPTICAL PHOTOMETRY
3. COLOR-MAGNITUDE DIAGRAM AND COLOR-COLOR DIAGRAM
4. DISCUSSION
REFERENCES

• Myo Jin Kim(Department of Astronomy, Yonsei University)
• Aeree Chung(Department of Astronomy, Yonsei University)
• Jong Chul Lee(Korea Astronomy and Space Science Institute)
• Sungsoon Lim(Peking University, No.5 Yiheyuan Road, Haidian District)
• Minjin Kim(Korea Astronomy and Space Science Institute/Korea University of Science and Technology)
• Jongwan Ko(Korea Astronomy and Space Science Institute)
• Joon Hyeop Lee(Korea Astronomy and Space Science Institute/Korea University of Science and Technology)
• Soung-Chul Yang(Korea Astronomy and Space Science Institute/The Observatories of the Carnegie Institution for Science)
• Hye-Ran Lee(Korea Astronomy and Space Science Institute/Korea University of Science and Technology)