The Landscape of Engine-Driven Explosions

Speaker: 
Anna Ho
Date: 
Friday, May 10, 2019 - 12:15pm to 1:00pm
In the conventional picture of a core-collapse supernova, the iron core collapses into a neutron star or a black hole, and a shockwave unbinds the star. In rare cases, accretion onto a rapidly rotating black hole acts as an "engine" that launches a jet. If that jet tunnels through the star, breaks out, and is pointed at the Earth, we detect a long-duration gamma-ray burst (GRB). There have been thousands of GRBs discovered, almost always by high-energy satellites. However, recent discoveries by optical surveys hint at diverse outcomes that are invisible to GRB satellites, such as jets that are choked inside the star. With the Zwicky Transient Facility (ZTF) we are conducting a systematic exploration of the broader landscape of engine-driven explosions, of which traditional GRBs are just one manifestation. I will show how unexpected arrivals to the landscape (such as AT2018cow) complicate the picture, revealing that some engine-driven explosions take place embedded in dense circumstellar material that was likely ejected in eruptive pre-explosion mass-loss episodes. 
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