2024MNRAS.528.3130K

We present a comparative study of the constrained parameters of active galactic nuclei (AGN) made by the public X-ray reverberation model KYNXILREV and KYNREFREV that make use of the reflection code XILLVER and REFLIONX, respectively. By varying the central mass (M_BH), coronal height (h), inclination (i), photon index of the continuum emission (Γ), and source luminosity (L), the corresponding lag-frequency spectra can be produced. We select only the simulated AGN, where their lag amplitude (τ) and M_BH follow the known mass-scaling law. In these mock samples, we show that τ and h are correlated and can possibly be used as an independent scaling law. Furthermore, h (in gravitational units) is also found to be positively scaled with M_BH, suggesting a more compact corona in lower-mass AGN. Both models reveal that the coronal height mostly varies between ∼5 and 15 r_g, with the average height at ∼10 r_g and can potentially be found from low- to high-mass AGN. Nevertheless, the KYNXILREV seems to suggest a lower M_BH and h than the KYNREFREV. This inconsistency is more prominent in lower-spin AGN. The significant correlation between the source height and luminosity is revealed only by KYNREFREV, suggesting the h-L relation is probably model-dependent. Our findings emphasize the differences between these reverberation models that raises the question of biases in parameter estimates and inferred correlations.