2012ApJ...754...87W

We observed three high-mass star-forming regions in the W3 high-mass star formation complex with the Submillimeter Array and IRAM 30 m telescope. These regions, i.e., W3 SMS1 (W3 IRS5), SMS2 (W3 IRS4) and SMS3, are in different evolutionary stages and are located within the same large-scale environment, which allows us to study rotation and outflows as well as chemical properties in an evolutionary sense. While we find multiple millimeter continuum sources toward all regions, these three subregions exhibit different dynamical and chemical properties, which indicate that they are in different evolutionary stages. Even within each subregion, massive cores of different ages are found, e.g., in SMS2, sub-sources from the most evolved ultracompact H II region to potential starless cores exist within 30,000 AU of each other. Outflows and rotational structures are found in SMS1 and SMS2. Evidence for interactions between the molecular cloud and the H II regions is found in the ¹³CO channel maps, which may indicate triggered star formation.