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tokens: for an unobscured AGN or for the Thomson-scattered emission of an obscured AGN, plus an APEC component representing the hot gas in the galaxy ( keV). We notice that the power-law component may also be partially attributed to emission from star formation and X-ray binaries, as discussed in Section 3.1.2 . The total absorption component is fixed to the Galactic value ( N H = 1.31 × 10 20 cm −2 , as given by the Colden Calculator with the NRAO data set 2 ). A similar value for the photon index () is obtained also when excluding the counts below 1.5 keV in order to avoid contamination by the hot gas. By fitting the 3.0–8.0 keV spectrum with a simple power law, we obtain a photon index . This low value is an indication that the source is heavily obscured and that the power law observed in the soft X-ray spectrum corresponds to the scattered component. However, due to the narrow energy interval considered, adding an obscured component to our fiducial model for the Chandra data does not improve the quality of the fit significantly, so that a combined fit with NuSTAR is needed to determine the real amount of obscuration. 3.1.2 Possible contribution from star formation IC 2497 is a luminous infrared galaxy (LIRG) with far-IR luminosity L FIR = 6.6 × 10 44 erg s −1 . Assuming the FIR–star formation rate relation of Kennicutt ( 1998 ), this corresponds to a star formation rate SFR ∼ 30 M ⊙ yr −1 . Using the relations of Ranalli et al. ( 2003 ) or Lehmer et al. ( 2016 ), the expected 2–10 keV luminosity is erg s −1 , which is comparable (within the large scatter of the correlations) to the observed 2–10 keV luminosity measured from the Chandra and NuSTAR spectra (we stress that all the used relations have a large scatter, so that the results have to be considered as an order of magnitude estimation). In addition, the low W1 - W2 colour, W1 - W2 = 0.3, suggests that the mid-IR emission is dominated by stellar emission (see Section 3.2.2 for a discussion of the mid-IR emission). Altogether, this points to a scenario where star formation provides an important contribution to the soft part of the X-ray spectrum. We will consider this component in the analysis below. 3.1.3 Phenomenological model Applying the unabsorbed power-law model described above to the 0.5–24.0 keV spectrum significantly underpredicts the hard X-ray counts observed with NuSTAR , especially in the 10.0–20.0 keV range (see Fig. 1 , left). This again is an indication that the source is highly obscured (e.g. Koss et al. 2016 ; Ricci et al. 2016a ). To infer the intrinsic column density N H and the X-ray luminosity of the source, we first fit the 0.5–24.0 keV spectrum with a phenomenological model which includes (1) an absorbed power law representing the intrinsic emission of the AGN, where we consider both photoelectric absorption and Compton scattering, (2) a second unabsorbed power law representing the scattered AGN component and the contribution from star formation, (3) the unabsorbed