XMM-Newton Ultra Narrow Deep Field survey II: X-ray spectral analysis of the brightest AGN population

In this work, we present the results of a detailed X-ray spectral analysis of the brightest AGNs detected in the XMM-Newton 1. 75 Ms Ultra Narrow Deep Field. We analyzed 23 AGNs that have a luminosity range of 10^42 - 10^46\, erg\, s^-1 in the 2 - 10\, keV energy band, redshifts up to 2. 66, and 10, 000 X-ray photon counts in the 0. 3 - 10\, keV energy band. Our analysis confirms the Iwasawa-Taniguchi effect, an anti-correlation between the X-ray luminosity (Lₓ) and the Fe-k Equivalent Width (EW₅₄) possibly associated with the decreasing of the torus covering factor as the AGN luminosity increases. We investigated the relationship among black hole mass (M₁₇), Lₓ, and X-ray variability, quantified by the Normalized Excess Variance (²ₑ₌ₒ). Our analysis suggest an anti-correlation in both M₁₇ - ²ₑ₌ₒ and Lₓ- ²ₑ₌ₒ relations. The first is described as ²ₑ₌ₒ M^-0. 26 0. 05₁₇, while the second presents a similar trend with ²ₑ₌ₒ Lₗ^-0. 31 0. 04. These results support the idea that the luminosity-variability anti-correlation is a byproduct of an intrinsic relationship between the BH mass and the X-ray variability, through the size of the emitting region. Finally, we found a strong correlation among the Eddington ratio (₄₃₃), the hard X-ray photon index (), and the illumination factor (A), which is related to the ratio between the number of Compton scattered photons and the number of seed photons. The (₄₃₃) -- (A) plane could arise naturally from the connection between the accretion flow and the hot corona.