Massive stars play a vital role in the star formation process, yet their own formation and their effects on subsequent generations of star formation are not well understood.
To improve our understanding, we have begun a detailed study of massive and active star formation regions in giant molecular clouds outside the Galactic Center. One of the main goals of this study is to identify and classify the Young Stellar Objects (YSOs) in each region by using Spitzer Space Telescope IRAC & MIPS mid-IR data and 2MASS/UKIDSS near-IR data and then identify the massive YSO candidates based on the SED models. Following this, YSO clusters will be identified based on spatial distributions of the detected sources.
Studying clusters with different evolutionary stages will help us to understand the formation and evolution process- es from beginning to end. This study will also provide significant information on how massive stars interact with their environment and how they affect the low-mass star formation in the cloud.