Relativistic Fe K$\alpha$ Line Revealed in the Composite X-ray Spectrum of Narrow Line Seyfert 1 Galaxies --- do their black holes have averagely low or intermediate spins?

Zhu Liu, Weimin Yuan, Youjun Lu +1

While a broad profile of the Fe K$\alpha$ emission line is frequently found in the X-ray spectra of typical Seyfert galaxies, the situation is unclear in the case of Narrow Line Seyfert…