Joint IAS Princeton University Astrophysics Colloquium

Abstract: In extreme astrophysical systems, such as black hole coronae and pulsar magnetospheres, the process of magnetic reconnection is significantly modified by strong radiative cooling. This cooling removes internal energy faster than it is...

Dramatic rises in ground-based light pollution in recent years as well as increasingly congested low-Earth orbits are leading to brightening night skies worldwide, with consequences reaching far beyond this decade. I share calculations of the...

Good estimations of stellar ages are important for a wide range of science cases, from understanding the evolution and habitability of exoplanetary systems to tracking back the cosmic history of our own and other galaxies. These ages, however, are...

Stars in nearly all globular clusters show complex relations among the abundances of light elements (up to Na).  Many also show anti-correlations of Mg and Al.  Until now, only one cluster (M15) conclusively showed any star-to-star variation in...

The gas-star formation-feedback "matter cycle" acts in many ways as the engine of galaxy evolution. Over the last decade, the PHANGS surveys have carried out surveys across the electromagnetic spectrum aimed at resolving galaxies into the...

Astronomers have been predicting and searching for planets beyond Neptune for almost 180 years. In all previous cases the predictions were based on bad data, bad physics, or both, and the predictions turned out to be wrong. In 2016, we joined this ...

We are living exciting times: we are now able to probe the most violent events of the Universe with diverse messengers (cosmic rays, neutrinos, photons and gravitational waves). One challenge to complete the multi-messenger picture resides in the...

For the last half-century, relativistic outflows accompanying the final collapse of massive stars have predominantly been detected via high-energy emission, as long-duration gamma-ray bursts (GRBs). Yet, it has long been hypothesized that GRBs are...

The standard model of cosmology has passed every test over the last twenty years. Yet it remains unsatisfactory, with 95% of the universe being dark components, whose nature we did not understand. Now, there are possible ‘cracks’ in the model, as...

Most of the power from an Active Galactic Nucleus is released close to the black hole, and thus studying accretion at event horizon scales—at the intersection of inflow and outflow—is essential for understanding how much matter accretes and grows...