DECIPHERING EVOLUTION OF CHANGING-LOOK AGN NGC 3516

Understanding the nature and origin of spectral variability provides us with keyinformation about the accretionoutflow mechanism in active galactic nuclei(AGN). Changinglook AGN show the most striking cases of spectral variability inAGN. NGC 3516 is a remarkable Seyfert1 galaxy, which over the last decade hasundergone major opticalUVXray spectral transformations, classifying it as achanginglook AGN. The extensive Swift monitoring of NGC 3516 shows that it iscurrently in a state of longterm transition between the extremely lowfluxstate and the historical highflux state. The proposed joint NuSTAR (60 ks) andXMMNewton (60 ks) observations of this transition state aim to gain newinsights into the mechanism of transition between the different states of the changinglook AGN. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]