1. THE STRUCTURE AND DYNAMICAL STATE OF ORION AND OTHER YOUNG STELLAR CLUSTERS Michael A. Kuhn 1, Eric D. Feigelson 1, Konstantin V. Getman 1, Adrian Baddeley 2, Leisa K. Townsley 1, Patrick S. Broos 1, Matthew S. Povich 3, Kevin L. Luhman 1, Heather A. Busk 1, Tim Naylor 4, Robert R. King 4, Gordon P. Garmire 1 1 Pennsylvania State University, USA, 2 University of Western Australia, Australia 3 California State Polytechnic University, USA, 4 University of Exeter, UK MYStIX = Massive Young Star Forming Complex Study in Infrared and X-ray More MYStIX: Talk by Eric Feigelson, Poster by Konstantin Getman Data available on astro-ph and at www.astro.psu.edu/mystix

2. Finding clusters of young stars using “finite mixture models” Layered structure to the Orion Nebula X-ray Selected IRE Selected

3. Typical Subcluster Properties Embedded Subclusters tend to be smaller Typical cluster cores have r=0.18 pc. Strong relation between core radius and central density. Similar to results interpreted by Pfalzner et al. (2009) as cluster expansion. Dynamical properties of subclusters.