Abstract:
Neutron stars are by far the strongest known magnets in the universe. Some of them (called magnetars) generate explosions via sudden dissipation of magnetic energy with power up to $10^{47}$ erg/s. These magnetic explosions emit giant gamma-ray flares observed in our and neighboring galaxies. Similar explosions in distant galaxies are proposed as the engines of the mysterious fast radio bursts (FRBs). They are many orders of magnitude brighter than pulsars and produce electromagnetic waves with dimensionless strength parameter exceeding unity, resembling nonlinear optics phenomena in laser plasma. Yet more powerful energy release occurs when two neutron stars merge. These cataclysmic events produce gravitational waves, neutrinos, and bright electromagnetic emission. Both mergers and isolated magnetar flares involve sudden heating up to MeV temperatures, creation of copious electron-positron pairs, and launching of ultra-relativistic outflows and shock waves. Recent numerical experiments shed some light on the extreme plasma physics in these events. Observations and simulations of the ultra-powerful bursts also provide insights into neutron star interior.
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This is a hybrid colloquium.
Colloquia are Wednesdays at 4:40 p.m. unless otherwise noted and will be in person at DUAN G1B20, as well as online via zoom and Youtube. If you are not a student/faculty member in physics, pre-register with Veronica Lingo (veronica.lingo@colorado.edu) to attend a lecture.
Masks are required for all colloquium attendees, regardless of vaccination status.
Watch via Youtube: https://youtu.be/k44m7A9Q6AI