tokens: Comptonization; case 2: partially absorbed pure reflection spectrum; case 3: partially absorbed Comptonization spectrum with reflection; case 4: partially absorbed Comptonization with reflection and variable local absorber. Parameters are: intrinsic column density associated with the direct (Compton) spectrum and relative covering fraction (pcf and pcf), intrinsic column density associated with the reflection spectrum and relative covering fraction (pcf and pcf), electron temperature, Compton parameter (see text), relative reflection factor, ionization parameter (see text), comp PS normalization, Gaussian line energy, Gaussian line equivalent width, power-law photon index (for the dust scattering halo), power-law normalization (for the dust scattering halo), JEM-X calibration constant and ISGRI calibration constant. All the quoted errors are 1 level ones. Notice that all models include an additional absorber to account for the interstellar absorption ( N H 8.310 21 cm 2 ). The FeK line flux has been expressed in terms of ergcm 2 s 1 instead of equivalent width in order to allow direct comparison with the lines flux from Model 2 (see Section 5 , for which measuring the equivalent width is problematic). 4 SPECTRAL MODELLING MODEL 1: PARTIALLY COVERED REFLECTED COMPTON SPECTRUM 4.1 Case 1: partially absorbed Comptonization We initially fitted our data using the Comptonization model comp PS in xspec (see Poutanen Svensson 1996 ) modified by the interstellar absorption ( tbnew in xspec ; Wilms, Allen McCray 2000 ) with a fixed column density of N H 8.310 21 cm 2 . We left the Thomson optical depth electron temperature kT e and the normalization in comp PS free to vary, while we fixed the seed photon temperature to kT bb 0.1keV (i.e. the seed photons are produced by a multicolour disc blackbody with an inner disc temperature of 0.1keV) and the inclination to 67 (see Khargharia etal. 2010 ). We also fixed to zero the ionization parameter since it only affects the reflection component, which is switched off in this case. We left all the remaining comp PS parameters fixed to their default values. Large residuals indicated that a more complex spectral model was required. Therefore, we added a neutral absorber partially covering the source ( tbnew_pcf ). The addition of a narrow Gaussian line to describe the ironK line (see King etal. 2015 ) was required to account for some residuals around 6.4keV. The line is unresolved in both the Swift /XRT and INTEGRAL /JEM-X spectra; therefore we fixed its width to 0.2keV. This model did not provide satisfactory fits, having 2 = 620.12 with 461d.o.f. and null hypothesis probability = 9.8210 8 . Large residuals especially above 10keV indicate that the spectrum likely shows a significant reflection component. 4.2 Case 2: partially absorbed pure reflection Since the emission from the dust scattering halo was at times significant in the sky region around the source, sometimes outshining the source itself (see
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