1ES 1927+654: Constraining the Late Stages of an Extreme Nuclear Transient

1ES 1927+654, the first changinglook AGN caught in the act of changing phases,has undergone extreme spectral changes over the last 3 years, including thedestruction and recreation of the Xray corona, possibly due to a tidaldisruption event in a preexisting AGN accretion disk. The latest XMMNewtonobservation is similar to the preoutburst observation from May 2011, butreveals a hint of an iron line, which was notably missing in the 2011observation. We propose one more simultaneous XMMNewton/NuSTAR campaign of 1ES1927+654, totaling 70 ks over two 35 ks observations, to probe the latestageevolution of this paradigmdefying AGN. The hard Xray spectrum will allow us totrack the heating of a newlyformed corona for the first time and determine whether the iron line has appeared. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]