complex. We propose that early processes of gas collapse in the main structure of the complex could have defined the progression of cluster formation across the complex with relatively small age differences from one group to another. However, triggering effects could act as catalysts for enhanced efficiency of formation at a local level, in agreement with previous studies.'
author:
- 'Carlos G. Román-Zúñiga, Jason E. Ybarra, Guillermo D. Megias, Mauricio Tapia, Elizabeth A. Lada and João F. Alves'
title: Star Formation Across the W3 Complex
---

Introduction \[s:intro\]
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In the current picture of star formation, Giant Molecular Clouds (GMC) are highly inefficient factories, in which only a small fraction of the available gas is converted into stars. Moreover, star forming regions in GMC complexes are highly heterogeneous. There is a considerable diversity among the stellar aggregations they produce. Differences are evident even at the level of their basic properties, e.g. sizes, numbers and density structures.

Aggregations of young stars in molecular clouds are classified as Embedded Star Clusters. These clusters are born as bound systems of gas and stars. Once gas is removed, embedded clusters may or may not stay bound. They either survive (e.g. open clusters), or dissolve 