Ζ Tau, a Post-interaction Binary

Be stars are usually thought to be born in binary interactions. The presence of the companion has been proposed to play a role in the peculiar X-ray emission recorded for a subgroup of Be stars called the γ Cas analogs. In this contribution, we report on a multiwavelength investigation of one of them, the Be binary ζ Tau. Using data from TESS, Chandra, SRG/eROSITA, and XMM-Newton, we derive the high-energy properties as a function of time and orbital phase. The results are then used to test the proposed γ Cas models.