Institute for Advanced Study Informal Astrophysics Seminar

The relationship between large-scale structure and the intrinsic shapes of galaxies is an important element of observational cosmology. These "intrinsic alignments" (IA) are the most significant source of astrophysical uncertainty in weak lensing measurements and must be understood if current and upcoming lensing surveys are to reach their full potential. I will present recent developments in understanding IA, including a model based on galaxy alignment with the tidal field. I will discuss efforts to probe IA through observation and simulation. I will show estimates of IA contamination in future lensing surveys and discuss our ability to remove it. Beyond its presence as a systematic uncertainty, IA can be a powerful probe of large-scale structure as well as the formation and evolution of galaxies and dark matter halos.