Simultaneous NuSTAR and XMM-Newton 0.5-80 keV spectroscopy of the Narrow
  Line Seyfert 1 galaxy SWIFT J2127.4+5654
  We present a broad band spectral analysis of the joint XMM-Newton and NuSTAR
observational campaign of the Narrow Line Seyfert 1 SWIFT J2127.4+5654,
consisting of 300 ks performed during three XMM-Newton orbits. We detect a
relativistic broadened iron K$\alpha$ line originating from the innermost
regions of the accretion disc surrounding the central black hole, from which we
infer an intermediate spin of $a$=$0.58^{+0.11}_{-0.17}$. The intrinsic
spectrum is steep ($\Gamma=2.08\pm0.01$) as commonly found in Narrow Line
Seyfert 1 galaxies, while the cutoff energy (E$_{\rm c}=108^{+11}_{-10}$ keV)
falls within the range observed in Broad Line Seyfert 1 Galaxies. We measure a
low-frequency lag that increases steadily with energy, while at high
frequencies, there is a clear lag following the shape of the broad Fe K
emission line. Interestingly, the observed Fe K lag in SWIFT J2127.4+5654 is
not as broad as in other sources that have maximally spinning black holes. The
lag amplitude suggests a continuum-to-reprocessor distance of about $ 10-20\
r_{\mathrm{g}}$. These timing results independently support an intermediate
black hole spin and a compact corona.
