Description:

Are there jets in Super-luminous Supernovae?

Deanne Coppejans, PhD | Northwestern University

The explosions of stars (supernovae, SNe) show a wide range of properties and characteristics. Super-luminous Supernovae (SLSNe) are the most luminous of all these explosions, but we do not yet know why this is the case. Where does all the extra energy come from? One of the leading theories is that this energy is provided by a so-called `central engine'. For example, the explosion could form a highly magnetic and rapidly rotating neutron star (the central engine) that would impart its energy to the SNe as it spins down. Jets are a key manifestation of a central engine, so determining whether SLSNe launch jets could answer this question. I will discuss a study in which we used high-sensitivity observations from radio telescopes and jet simulations to put the strongest constraints to date on the existence of jets (and their properties) in SLSNe. Thereafter I will outline the steps necessary to conclusively determine whether SLSNe launch jets.

Discovering black holes with Gaia

Katie Breivik

Stellar-mass black-hole binaries are elusive stellar remnants that hold many keys to understanding the formation and evolution of binary star systems. Traditionally, observations of stellar mass black holes were only possible through X-ray observations of close binary systems. However, black holes have recently been discovered through gravitational wave observations and radial velocity measurements. In this talk, I will show some recent work that aims to predict the population of black holes orbiting luminous companions that could be astrometrically discovered by Gaia. I will also show how this population is complementary to populations of black holes observable through X-ray or gravitational wave observations and could potentially give insights into the common envelope phase of binary evolution.