The 8 keV line in the X-ray bright Seyfert galaxy UGC 3973

Two short exposures of the bright, radioquiet Seyfert1.2 galaxy UGC3973 wereconducted with XMM as part of an AGN snapshot survey. During one of theseobservations a narrow 8keV (rest frame) linelike emission feature was detectedwith the pn instrument. An instrumental origin was ruled out. The detection wasseriously scrutinised and found to be significant at 96.098.4% confidence,depending what a priori assumptions were made. We propose three, 20ksobservations (60ks total) of UGC3973 spread over AO5. The proposed programmewill allow investigation of the significance of the feature, its variability,and its origin. In addition, UGC3973 has demonstrated significant flux andspectral variability over similar time periods as proposed here. This will allow truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]