Abstract

Torque switching is a behavior seen in accreting pulsars where intervals of steady spin-up alternate with intervals of steady spin-down, with the transitions between these intervals being rapid compared to the their duration. This behavior was first noted in the BATSE/GRO data in the 1990's. Surprisingly it is seen in both Roche-lobe overflow and wind-outflow systems. We present observations from Fermi/GBM and other instruments, and discuss some of their implications.