Presentation #119.03 in the session HEAD I: The Shaw Prize in Astronomy.
For many years, Anomalous X-ray Pulsars (AXPs) were a significant mystery in high-energy astrophysics, thought to be accreting neutron-star X-ray binaries but producing high X-ray luminosities in spite of the absence of any apparent companion donor star. Regular systematic monitoring of these sources over many years, first with the Rossi X-ray Timing Explorer and later with Swift, eventually revealed them to be magnetars and close cousins of the “soft gamma repeaters” (SGRs) Here I review the path that led to unlocking the mystery of AXPs, the overall unification of AXPs and SGRs with the radio pulsar and neutron star population, and conclude with their potential relevance to Fast Radio Bursts.