Joint IAS Princeton University Astrophysics Colloquium

Time-domain surveys are finding tens of thousands (and soon millions) of transient events.  But how do we make new discoveries of rare and exotic events? And how do we figure out what causes and powers them? I will discuss several approaches that...

Abstract: Current pulsar timing array (PTA) projects are galactic-scale gravitational-wave (GW) detectors whose sensitivity is approaching the point at which a signal should become clearly detectable. Despite the strong evidence reported in the...

Abstract: Black hole mergers carry information about some of the least understood stages of stellar evolution, the dynamics of dense stellar systems, and the growth of compact objects through accretion. Gravitational-wave observations offer a way to...

Transient surveys and follow up efforts are providing a wealth of new data on the variety of ways in which tidal disruption events manifest across the electromagnetic spectrum. Understanding these light curves and spectra are key to using these...

The James Webb Space Telescope (JWST) is finding earlier and brighter sources than expected. In this talk I will explore how these new observations fit (or don’t) within our cosmological and galaxy-formation models. First, I will discuss the...

The distribution of matter on very large scales - the so-called large-scale structure - contains clues, hidden within its statistics, about the origin and evolution of the Universe. While the gravity-only evolution of dark matter can be modelled...

Abstract: Astronomy's current model of galaxy evolution is built on a foundation of hierarchical growth, in which small galaxies merge together to form larger ones.  In addition to the simple accrual of mass, this merging process is predicted to...

Abstract: The first detection of gravitational waves in 2015, created by the merger of black holes more than a billion years ago, was followed by many other signals from black holes. In 2017, the merger of neutron stars was detected by LIGO and...

The origin of extraterrestrial energetic particles ("cosmic rays") has puzzled scientists since the pioneering discovery by Victor Hess in 1912. In the last decade, however, modern supercomputers and multi-wavelength observations have opened new...

Supermassive black hole binaries (SMBHBs) should be common in galactic nuclei as a result of frequent galaxy mergers. Yet they remain undetectable, especially during the final stage of their evolution. At this stage, SMBHBs are expected to emit...