Astronomy Colloquium Series
Dr. Coral Wheeler, Dubridge Postdoctoral Fellow at TAPIR California Institute of Technology
"Sweating the small stuff: small scale challenges to LCDM and dwarf galaxy simulations at the high resolution limit."
The currently favored cosmological paradigm — Lambda Cold Dark Matter Theory (LCDM) — has been widely successful in predicting the counts, clustering, colors, morphologies, and evolution of galaxies on large scales, as well as a variety of cosmological observables. Despite these successes, several challenges have arisen to this model in recent years, most of them occurring at the smallest scales — those of dwarf galaxies (M* < 10^9 Msun). I will review several of these small scale challenges, including the Missing Satellites Problem, the Cusp-Core Controversy, and the tension between the regularity of galactic scaling relations and the diversity of rotation curves. In reviewing current attempts to rectify these issues — many of which rely on the inclusion of baryonic effects in simulations — I will introduce a new set of high resolution cosmological hydrodynamic zoom-in simulations (GIZMO/FIRE2) of isolated dwarf galaxies — the highest resolution ever run to z=0. This new generation of mbar ~ 10 Msun simulations marks a transition point between simulations that treat star formation within a single stellar population in the aggregate, and simulations that model the individual collapse and fragmentation of a molecular clouds into individual stars, and will allow us to probe smaller physical scales than previously possible in a cosmological simulation.
The currently favored cosmological paradigm — Lambda Cold Dark Matter Theory (LCDM) — has been widely successful in predicting the counts, clustering, colors, morphologies, and evolution of galaxies on large scales, as well as a variety of cosmological observables. Despite these successes, several challenges have arisen to this model in recent years, most of them occurring at the smallest scales — those of dwarf galaxies (M* < 10^9 Msun). I will review several of these small scale challenges, including the Missing Satellites Problem, the Cusp-Core Controversy, and the tension between the regularity of galactic scaling relations and the diversity of rotation curves. In reviewing current attempts to rectify these issues — many of which rely on the inclusion of baryonic effects in simulations — I will introduce a new set of high resolution cosmological hydrodynamic zoom-in simulations (GIZMO/FIRE2) of isolated dwarf galaxies — the highest resolution ever run to z=0. This new generation of mbar ~ 10 Msun simulations marks a transition point between simulations that treat star formation within a single stellar population in the aggregate, and simulations that model the individual collapse and fragmentation of a molecular clouds into individual stars, and will allow us to probe smaller physical scales than previously possible in a cosmological simulation.
Building: | West Hall |
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Website: | |
Event Type: | Lecture / Discussion |
Tags: | Astronomy, Climate and Space Sciences and Engineering, Physics, Science |
Source: | Happening @ Michigan from Department of Astronomy, Department of Physics, Michigan Institute for Research in Astrophysics |