Probing Formation from Stars to Planets: Accretion, Binarity and Disks in Young Brown Dwarfs

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The discovery of extrasolar planets over the last decade and a half ranks among the most important advances in the history of astronomy. More than three hundred have been found so far, in a plethora of stellar system architectures, and down to a few Earth masses. Determining the formation mechanism, properties and habitability of these planets (and those of lower mass bound to be detected in coming years) is at the cutting edge of current astrophysical research. These questions are in turn intimately linked to the fundamental issue of star formation, since planets form out of the accretion disks that are an integral outcome of the star-formation process and that ultimately determine the final stellar mass. Finally, the formation and properties of both stars and planets are closely tied to those of brown dwarfs: substellar bodies that straddle the mass range between stars and planets and share many features with both. In this project, I investigate the inter-linked origins of stars, brown dwarfs and planets by addressing 3 broad questions: 1) How do young stars and brown dwarfs accrete material from their surrounding accretion disks? 2) How do brown dwarfs form? 3) Can planets form around brown dwarfs? The research entails a variety of observational techniques, from high-resolution spectroscopy and spectropolarimetry to resolved imaging with adaptive optics, deployed over wavelengths ranging from the optical to sub-millimetre and using both ground- and space-based facilities, allied with theoretical analysis and numerical modeling. The results of the project should provide a broad and comprehensive picture of the physical processes that underlie the formation of objects all the way from from stellar down to planetary masses.