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arXiv · 2205.07904

The lively accretion disk in NGC 2992. II. The 2019/2021 X-ray monitoring campaigns

R. Middei·A. Marinucci·V. Braito·S. Bianchi·B. De Marco·A. Luminari·G. Matt·E. Nardini·M. Perri·J. N. Reeves·F. Vagnetti
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Abstract

We report on the short and long term X-ray properties of the bright nearby Seyfert 2 galaxy NGC 2992, which was extensively observed with Swift, XMM-Newton and NuSTAR. Swift targeted the source more than 100 times between 2019 and 2021 in the context of two monitoring campaigns. Both time-averaged and time-resolved analyses are performed, and we find that the short-to-long term spectral properties of NGC 2992 are dominated by a highly variable nuclear continuum. The source varied in the 2-10 keV energy band from 0.6 to 12 $\times$ 10$^{-11}$ erg cm$^{-2}$ s$^{-1}$ during the two year long Swift monitoring. The fastest 2-10 keV flux change (by a factor of $\sim60\%$) occurred on a timescale of a few hours. The overall emission spectrum of the source is consistent with a power law-like continuum ($\Gamma=1.69\pm0.01$) absorbed by a constant line-of-sight column density N$_{H}=(7.8\pm0.1)\times$ 10$^{21}$ $\rm cm^{-2}$. The reflected emission is likely due to matter with an average column density N$_{\rm H}=(9.6\pm2.7)\times$ 10$^{22}$ $\rm cm^{-2}$, thus NGC 2992 appears to have a globally Compton-thin circumnuclear medium. This scenario is fully supported by an independent analysis of the fractional variability and by XMM-Newton multi-year spectra.

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R. Middei, A. Marinucci, V. Braito, S. Bianchi, B. De Marco, A. Luminari, G. Matt, E. Nardini, M. Perri, J. N. Reeves, F. Vagnetti. 2022-05-16. The lively accretion disk in NGC 2992. II. The 2019/2021 X-ray monitoring campaigns. https://doi.org/10.1093/mnras/stac1381

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