Anomalous X-ray pulsars (AXPs) are an observational manifestation of magnetars—young, isolated, highly magnetized neutron stars. These energetic X-ray pulsars are characterized by slow rotation periods of ~2–12 seconds and large magnetic fields of ~1013–1015 gauss (1 to 100 gigateslas). As of 2017[update], there were 12 confirmed and 2 candidate AXPs known.[1] The identification of AXPs with magnetars was motivated by their similarity to soft gamma repeaters.
| The AXP candidates and their estimated rotation period in seconds, as of 2003[update], were: | ||
| AXP 1E 2259+586 | 6.98 | |
| AXP 1E 1048-59 | 6.45 | |
| AXP 4U 0142+61 | 8.69 | |
| AXP 1RXS 1708-40 | 11.0 | |
| AXP 1E 1841-045 | 11.8 | |
| AXP AXJ1844-0258 | 6.97 | |
| AXP CXJ0110-7211 | 5.44 | |
| The second, fourth, and last names have been abbreviated. | ||