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arXiv · 1908.03112

The coronal temperature of NGC 4388 and NGC 2110 measured with INTEGRAL

F. Ursini·L. Bassani·A. Malizia·A. Bazzano·A. J. Bird·J. B. Stephen·P. Ubertini
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Abstract

We aim to measure the physical properties of the hot X-ray corona of two active galactic nuclei, NGC 4388 and NGC 2110. We analysed the hard X-ray (20-300 keV) INTEGRAL spectrum in conjunction with archival XMM-Newton and NuSTAR data. The X-ray spectrum of both sources is phenomenologically well described by an absorbed cut-off power law. In agreement with previous results, we find no evidence of a Compton reflection component in these sources. We obtain a high-energy cut-off of $200^{+75}_{-40}$ keV for NGC 4388 and $320^{+100}_{-60}$ keV for NGC 2110. A fit with a thermal Comptonisation model yields a coronal temperature of $80^{+45}_{-20}$ keV and $75^{+20}_{-15}$ keV, respectively, and an optical depth of approximately two, assuming a spherical geometry. The coronal temperature and luminosity of both sources are consistent with pair production that acts as a thermostat for the thermal plasma. These results emphasise the importance of good signal-to-noise X-ray data above 100 keV to probe the high-energy emission of AGNs.

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F. Ursini, L. Bassani, A. Malizia, A. Bazzano, A. J. Bird, J. B. Stephen, P. Ubertini. 2019-08-08. The coronal temperature of NGC 4388 and NGC 2110 measured with INTEGRAL. https://doi.org/10.1051/0004-6361/201936273

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