Spectral and Temporal Properties of the Ultra-Luminous X-Ray Pulsar in M82 From 15 Years of Chandra Observations and Analysis of the Pulsed Emission Using NuSTAR
Murray Brightman et al 2016 ApJ 816 60
A remarkably bright pulsar recently discovered in M82 is not a transient, as was previously believed; analysis of Chandra observations show it has been highly active throughout the last 15 years.