Steve Furlanetto: Research

Research Interests:
Structure Formation

A combination of observations, analytic studies, and numerical simulations have now essentially confirmed our basic paradigm of structure formation. Tiny fluctuations in the matter density (generated at inflation) grow through gravitational instability. Asymmetries in the growth mean that collapse occurs first along a single axis, creating a "pancake" or sheet, then along a second axis, forming a filament, before finally collapsing fully to form a galaxy or galaxy cluster. The resulting picture has a "cosmic web" of filaments with galaxies sitting at their intersections; the two panels above show simulations of the cosmic web as it might be seen in Lyman-alpha emission.

Although the basic properties of this model are now well-understood, many questions do remain. Some of these are:

Voids: The empty voids between filaments are not entirely empty, though their galaxies are few and far between. Large redshift surveys have now begun to explore these regions and we can study their properties in detail. These can potentially teach us about both cosmology and galaxy formation.

Galaxy Formation and Clustering: Clustering is usually thought of as a property of the large-scale structure itself. But of course our tracers of clustering are luminous galaxies - whose properties are determined by the complicated physics of galaxy formation. I am interested in how these processes can bias our view of galaxy clustering. For example, are merging galaxies (which are more likely to host starbursts) more clustered than "normal" galaxies?