High Energy Astrophysics Seminar - Daniel Perley (Liverpool University)

Thu, 12/11/2020 - 13:00 to 14:00


Title: A Complete Survey of the Catastrophic Universe


Abstract:While it looks static to the naked eye, the night sky is filled withactivity: a star explodes somewhere in the observable universe once everysecond. The vast majority of these explosions go unheralded, but a newgeneration of synoptic optical surveys are finally enabling us to chart indetail the fourth-dimension of survey space: the time-domain. The most powerfulsuch facility currently in operation, the Zwicky Transient, is providing majoradvances in understanding of the nature of the dynamic universe in two ways.First, we are finally able to systematically map out the full diversity oftransient optical phenomena systematic manner.  I will describe how we aretethering ZTF to a variety of robotic telescopes to obtain classifications forpractically every bright SN that occurs in the Northern nighttime sky, allowingus to provide secure rate measurements, luminosity functions, and toexplore  the diversity of behavior for everything from low-mass stellarmergers to superluminous supernovae. Second, ZTF provides a  highlyefficient means of hunting for the rarest, fastest, and most extremeexplosions: off-axis gamma-ray bursts, "dirty" fireballs  frommoderately-relativistic jets, and now an entirely new class of very luminousmulti-wavelength transient that may originate from  the direct collapse ofa highly-rotating star to a black hole. I will describe the strange zoo ofphenomena we have found so far and what we have learned from them about theend-stages of stellar evolution and the nature of the compact "centralengines" that power jets and winds in collapsing stars.


Topic: HighEnergy Astrophysics Seminar

Time: 13:00(12:00 CET)


Join ZoomMeeting



Meeting ID:891 0952 3146