Astrophysics Seminars

We believe that supermassive black holes reside at the center of massive galaxies, where they can shine as an active galactic nucleus (AGN) when supplied with gas to accrete.  These black holes are believed to be important for regulating gas cooling...

Finding low-scatter relationships in properties of complex systems (e.g., stars, supernovae, galaxies) is important to gain physical insights into them and/or to estimate their distances/masses. As the size of simulation/observational datasets grow...

Abstract: Pulsar radio emission may be generated in pair discharges which fill the pulsar magnetosphere with plasma as an accelerating electric field is screened by freshly created pairs. In this talk we present a simplified analytic theory for the...

It was suggested over thirty years ago that microscopic black holes can exponentially enhance the decay rate of a metastable false vacuum. The interest in this phenomenon has revived recently due to its possible phenomenological relevance for the...

In this talk, I will briefly discuss our work on understanding the 3D morphology of magnetic fields associated with molecular clouds. To study the 3D magnetic fields, we first proposed and demonstrated a new technique to determine the line-of-sight...

With thousands of known transiting exoplanets, many as small as the Earth, our detection capabilities are beginning to border on that necessary to detect the largest moons found in our solar system. Exomoons would offer new opportunities to...

The orbital evolution of binary systems perturbed by external tidal forces represents one of the oldest problems in celestial mechanics.   Interest in this class of problems has resurged recently due to the discovery of various exotic astrophysical...

Although today’s nuclear arsenals are not much in the news, they pose enormous risks for all humanity. Moreover, many treaties that have reduced the threat of nuclear weapons are now being abandoned, and enormous resources are scheduled to be spent...

Particularly with the advent of Gaia, we can use Galactic SNRs as new probes of supernova progenitors.  In particular, we can constrain how many were binaries or triples at death and how
many of these systems survived.  We can also isolate the...

The giant impact theory for the formation of the Moon suggests that a planetary impactor struck the proto-Earth in an oblique collision shortly after the formation of the solar system. This collision produces liquid and vapor debris, drawn from the...