Astrophysics Seminars

The expansion history of the Universe prior to Big Bang nucleosynthesis is unknown. This ignorance profoundly limits our understanding of dark matter: we cannot calculate its relic abundance without knowing when the Universe became radiation...

The new era of exoplanetary discovery has begun to allow a statistical understanding of planetary distributions to inform our knowledge of planet formation and migration. These data now allow us to start inferring the relative importance of various...

POLARBEAR is a millimeter wave polarimeter operating from 5,200 meters in the Atacama Desert of northern Chile. The instrument's 3.5 arcminute beam enables measurements of the polarized cosmic microwave background (CMB) lensing signal. After briefly...

Binary black hole mergers in the presence of gaseous accretion flows are prime candidates for simultaneous observations of both gravitational waves and electromagnetic signals. I will present the results of 2D hydrodynamical simulations of...

This talk presents a simple, unified picture for the formation and evolution of star clusters. These objects are important in the structure and evolution of galaxies, primarily as the sites of star formation and stellar feedback. The talk is...

Bars are a key signpost in the evolutionary history of a disk galaxy. When a disk is sufficiently massive, dynamically cold and rotationally supported, and sufficient time has elapsed for the baryonic matter to exchange energy and angular momentum...

Large-scale magnetic fields exist in cosmic structures such as galaxies and galaxy clusters. Moreover, recent gamma ray observations have suggested the existence of magnetic fields even in void regions. In this talk I will explain how such large...

Stars are tidally disrupted by supermassive black holes when they are scattered onto low-pericenter orbits in distant galactic nuclei. Accretion of the bound debris results in a multiwavelength flare with bolometric luminosity comparable to or...