Multi-messenger astronomy with continuous gravitational waves now and in the 2030s

Gravitational waves are not just transients. Continuous waves from long-lived quasinormal modes or deformations of neutron stars will be a game changer in multi-messenger astronomy over the next decade. Many continuous wave searches are guided by radio or x-ray observations, such as pulsar timing or finding small pulsar wind nebulae or supernova remnants. I summarize multi-messenger continuous wave detection prospects, focusing on gravitational wave detectors leading up to Cosmic Explorer and on concurrently operating radio and x-ray observatories such as SKA, ngVLA, eXTP, and ATHENA.