Prompt Periodicity in the GRB 211211A Precursor: Black-hole or magnetar engine?

Gavin P. Lamb, Thomas Baxter, Conor M. B. Omand +18

The merger origin long GRB 211211A was a class (re-)defining event. A precursor was identified with a $\sim 1$ s separation from the main burst, as well as a claimed candidate quas…