IAS/PU Joint Astrophysics Colloquium

Heavy Element Synthesis in the Universe

Enrico Ramirez-Ruiz
University of California, Santa Cruz
April 28, 2015

The source of about half of the heaviest elements in the Universe has been a mystery for a long time. Although the general picture of element formation is well understood, many questions about the nuclear physics processes and particularly the astrophysical details remain to be answered. Here I focus on advances in our understanding of the origin of the heaviest and rarest elements in the Universe.

Enigmatic Enceladus

Peter Goldreich
California Institute of Technology & Institute for Advanced Study
April 7, 2015

Saturn’s satellite Enceladus displays a bewildering array of thermal activity. I will describe our attempts to understand these phenomena in terms of tidal heating associated with the 2:1 mean motion resonance between Enceladus and Dione. Then I will argue that Enceladus and the other midsize satellites of Saturn are young.

Measuring and Modelling Redshift-space Distortions in the Galaxy Distribution

John Peacock
University of Edinburgh
March 3, 2015

Deviations from a uniformly expanding universe are of interest in modern cosmology, most particularly because the amplitude of such peculiar motions measures the strength of gravity on scales of roughly 10-100 Mpc. I will review various recent attempts to measure these velocity effects in leading galaxy surveys, together with new rapid approximate means of generating the simulated universes that are needed in order to extract validated results from the data.