The Low-temperature Corona in ESO 511-G030 Revealed by NuSTAR and XMM-Newton
We present the results from a coordinated XMM-Newton + NuSTAR observation of the Seyfert 1 galaxy ESO 511−G030. With this joint monitoring program, we conduct a detailed variability and spectral analysis. The source remained in a low flux and very stable state throughout the observation period, although there are slight fluctuations of flux over long timescales. The broadband (0.3–78 keV) spectrum shows the presence of a power-law continuum with a soft excess below 2 keV, a relatively narrow iron Kα emission (∼6.4 keV), and an obvious cutoff at high energies. We find that the soft excess can be modeled by two different possible scenarios: a warm (kTₑ ∼ 0.19 keV) and optically thick (τ = 18–25) Comptonizing corona or a relativistic reflection from a high-density (log[nₑ_/cm}⁻³] = 17.1-18.5) inner disk. All models require a low temperature (kTₑ ∼ 13 keV) for the hot corona.
© 2023. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. This work was supported by the National Natural Science Foundation of China (NSFC), grant No. 11973019; the Natural Science Foundation of Shanghai, grant No. 22ZR1403400; the Shanghai Municipal Education Commission, grant No. 2019-01-07-00-07-E00035; and Fudan University, grant No. JIH1512604. J.J. acknowledges support from the Leverhulme Trust, the Isaac Newton Trust, and St Edmund's College, University of Cambridge.
Published - Zhang_2023_ApJ_949_4.pdf