Alessandra De Rosa (INAF/IASF-Roma, Italy)

Measuring strong gravity effects in AGN observed with LOFT

Thanks to its sensitivity and broad energy range (3-50 keV), LOFT will be able to determine with very high
signal to noise and accurate continuum subtraction the profile the Fe K-lines. Detailed simulations show that
observations with 1e4 s exposure will provide a high enough S/N to detect broad Fe lines in 1 mCrab flux
AGN, measuring the inner radius of the disk down to the marginally stable orbit and, from this, derive the
spin of the BH with a 20% accuracy (10% for fast spin). Moreover the very high throughput of LOFT will
permit to investigate the Fe line response to flares, and reveal the orbital motion of individual blobs providing
BH mass and spin with 25% and 20% accuracy. In addition, thanks to the wide energy band and the large
effective area above 10 keV, the variation of the reflection continuum can be measured with a 2% accuracy.