[PAST EVENT] Physics Colloquium
September 28, 2012
4pm - 5pm
Abstract: The spatial distribution of young stars - a critical observation in understanding the physics of star formation - is typically described in terms of clusters. However, the hierarchical clustering of young stars suggests that the identification of individual clusters is arbitrary, and probably not the most direct way to characterize the distribution. Indeed, a search for statistically significant clustering scales reveals a surprisingly simple answer: the clustering of stars is mostly scale-free, except for one transition scale at about the thickness of the galaxy disk. Moreover, comparing the 3D fractal dimension of the youngest stars and gas in the galaxy M33 reveals a coherent picture where very young stars are as clustered as the molecular gas out of which they formed, and slightly older stars are as clustered as the ionized gas they create.