The NuSTAR view of the Seyfert Galaxy HE 0436-4717
  We present the multi epoch spectral analysis of HE 0436-4717, a bright
Seyfert 1 galaxy serendipitously observed by the high energy satellite NuSTAR
four times between December 2014 and December 2015. The source flux shows
modest variability within each pointing and among the four observations.
Spectra are well modelled in terms of a weakly variable primary power law with
constant photon index ($\Gamma$=2.01$\pm$0.08). A constant narrow \ion{Fe}
K$\alpha$ emission line suggests that this feature has an origin far from the
central black hole, while a broad relativistic component is not required by the
data. The Compton reflection component is also constant in flux with a
corresponding reflection fraction R=0.7$^{+0.2}_{-0.3}$. The iron abundance is
compatible with being Solar (A$_{Fe}$=1.2$^{+1.4}_{-0.4}$), and a lower limit
for the high energy cut-off E$_c$>280 keV is obtained. Adopting a
self-consistent model accounting for a primary Comptonized continuum, we obtain
a lower limit for the hot corona electron temperature kT$_e$>65 keV and a
corresponding upper limit for the coronal optical depth of $\tau_e$<1.3. The
results of the present analysis are consistent with the locus of local Seyfert
galaxies in the kT$_e$-$\tau_e$ and temperature-compactness diagrams.
