We present our AKARI study of massive star forming regions where a large-scale cloud-cloud collision possibly contributes to massive star formation. Our targets are Spitzer bubbles, which consist of two types of bubbles, closed and broken ones; the latter is a candidate of the objects created by cloud-cloud collisions. We performed mid- and far-infrared surface photometry toward Spitzer bubbles to obtain the relationship between the total infrared luminosity, LIR, and the bubble radius, R. As a result, we nd that LIR is roughly proportional to R where  = 2:10:4. Broken bubbles tend to have larger radii than closed bubbles for the same LIR.

ABSTRACT
1. INTRODUCTION
2. OBSERVATION AND ANALYSIS
    2.1. Sample Selection
    2.2. Analysis Method
3. RESULTS AND DISCUSSION
4. SUMMARY
REFERENCES

• Yasuki Hattori(Graduate School of Science, Nagoya University)
• Hidehiro Kaneda(Graduate School of Science, Nagoya University)
• Daisuke Ishihara(Graduate School of Science, Nagoya University)
• Mitsuyoshi Yamagishi(Graduate School of Science, Nagoya University)
• Toru Kondo(Graduate School of Science, Nagoya University)
• Hidetoshi Sano(Graduate School of Science, Nagoya University)