Dartmouth Events

Abstract: Highly magnetized neutron stars are a source of powerful transients observed in different frequency bands, like the fast radio bursts (FRBs) with an associated hard X-ray burst from the Galactic magnetar SGR 1935+2154. The origin of such outbursts is still unknown, and the simultaneous observation of energetic X-ray blasts and short but luminous coherent radio pulses poses a fundamental challenge to extreme plasma astrophysics. In this colloquium, I present a global model explaining various elements of magnetar bursting activities. Surface motions of the crust shift the frozen-in footpoints of magnetic field lines and inevitably twist the inner magnetar magnetosphere. With strong analogies to solar eruptions, I discuss criteria for the instability of twisted flux bundles in highly magnetized magnetospheres. I then demonstrate how their energy release can drive magnetar X-ray bursts, giant flares, and FRBs in the outer magnetar magnetosphere. 

***Join before the Colloquium at 3:00 pm for coffee, cookies and brownies from Lou's in Wilder 103!***

Hosted by Professor Yi-Hsin Liu