The lively accretion disc in NGC 2992 - II. The 2019/2021 X-ray monitoring campaigns
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 × 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 $\sim 60{{\ \rm per\ cent}}$) occurred on a time-scale of a few hours. The overall emission spectrum of the source is consistent with a power law-like continuum (Γ = 1.69 ± 0.01) absorbed by a constant line-of-sight column density NH = (7.8 ± 0.1) × 1021$\rm cm^{-2}$. The reflected emission is likely due to matter with an average column density NH = (9.6 ± 2.7) × 1022$\rm cm^{-2}$, 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 multiyear spectra.
- Publication:
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Monthly Notices of the Royal Astronomical Society
- Pub Date:
- August 2022
- DOI:
- arXiv:
- arXiv:2205.07904
- Bibcode:
- 2022MNRAS.514.2974M
- Keywords:
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- galaxies: active;
- galaxies: Seyfert;
- X-rays: galaxies;
- X-rays: individuals (NGC 2992);
- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 21 pages, 17 figures. Accepted for publication in MNRAS