Astrophysics Seminars

Apr
13
2017

Institute for Advanced Study Informal Astrophysics Seminar

Nonlinear Tides in Coalescing Binary Neutron Stars
Nevin Weinberg
11:00am
Coalescing binary neutron stars are among the most promising sources for ground-based gravitational wave detectors such as advanced LIGO. Tidal interactions in such systems extract energy from the orbit and, at some level, modify the gravitational...
Mar
30
2017

Institute for Advanced Study Informal Astrophysics Seminar

Search for Intergalactic Magnetic Fields and Implications
11:00am
The ongoing search for intergalactic magnetic fields using blazar observations suggests field strength in the 10^(-14) to 10^{-17} G range on tens of Mpc length scales. Such fields can have important implications for the early universe and also...
Mar
23
2017

Institute for Advanced Study Informal Astrophysics Seminar

Secular Evolution in Discrete Self-Gravitating Stellar Discs
11:00am
Fluctuations in a stellar system's gravitational field cause the orbits of stars to evolve. These fluctuations can either originate from external perturbers (e.g. flybys), or from the intrinsic discreteness of the system (e.g. giant molecular clouds...
Mar
16
2017

Institute for Advanced Study Informal Astrophysics Seminar

Mass Ejection in Common Envelope Interactions: Observational evidence begins to constrain a long-standing theoretical problem
11:00am
It is becoming an observational reality to catch common envelope episodes and stellar mergers in action as astronomical transients. We think that most compact binaries pass through these phases, where one star becomes engulfed by the envelope of its...
Mar
09
2017

Institute for Advanced Study Informal Astrophysics Seminar

Uncovering the Signatures of Obscured AGN in Mergers
Laura Blecha
11:00am
Galaxy mergers have long been implicated as drivers of supermassive black hole (BH) and galaxy co-evolution, but the relative importance of mergers for fueling active galactic nuclei (AGN) is still uncertain. In large part, the ongoing debate stems...
Mar
02
2017

Institute for Advanced Study Informal Astrophysics Seminar

Seeding Massive Black Holes in Galaxies
11:00am
Although quasar activity is believed to be associated with galaxy mergers, at least one of the progenitor galaxies must host a pre-existing massive black hole (MBH). Furthermore, mergers make spheroids, yet there are galaxies lacking classical...
Mar
01
2017

Institute for Advanced Study Informal Astrophysics Seminar

The Sizes of Kuiper Belt Objects
Yanqin Wu
2:00pm
TITLE & ABSTRACT ADDED - Kuiper Belt Objects are often touted as fossil records of the early Solar System. So what can we learn from them? Here I will discuss one important aspect, their primordial size distribution: is it top-heavy with most of the...
Feb
23
2017

Institute for Advanced Study Informal Astrophysics Seminar

Cosmology of Flavor-mixed Dark Matter
11:00am
The standard Lambda-CDM cosmological model is successful at describing the distribution of matter at large scales but faces problems at galactic scales. Pundits blame for this the poorly understood or modeled baryonic physics, e.g., star formation...
Feb
16
2017

Institute for Advanced Study Informal Astrophysics Seminar

Observational Tools for Nonlinear Large-Scale Structure
Marcel Schmittfull
11:00am
We are planning to run a large program of cosmological large-scale structure surveys over the next decade. By probing more modes than the CMB, we hope to learn new aspects about dark energy, the origin of the universe or neutrinos. However, many of...