X-Ray Reverberation Mapping of Ark 564 Using Gaussian Process Regression

Lewin C, Kara E, Wilkins D, Mastroserio G, Garcia JA, Zhang RC, Alston WN, Connors R, Dauser T, Fabian A, Ingram A, Jiang J, Lohfink A, Lucchini M, Reynolds CS, Tombesi F, Van Der Klis M, Wang J (2022)

Publication Type: Journal article

Publication year: 2022

Journal

Astrophysical Journal American Astronomical Society

Book Volume: 939

Journal Issue: 2

DOI: 10.3847/1538-4357/ac978f

Abstract

Ark 564 is an extreme high-Eddington Narrow-line Seyfert 1 galaxy, known for being one of the brightest, most rapidly variable soft X-ray AGN, and for having one of the lowest temperature coronae. Here we present a 410-ks NuSTAR observation and two 115-ks XMM-Newton observations of this unique source, which reveal a very strong, relativistically broadened iron line. We compute the Fourier-resolved time lags by first using Gaussian processes to interpolate the NuSTAR gaps, implementing the first employment of multi-task learning for application in AGN timing. By fitting simultaneously the time lags and the flux spectra with the relativistic reverberation model RELTRANS, we constrain the mass at 2.3+2.6/-1.3x10(6)M?, although additional components are required to describe the prominent soft excess in this source. These results motivate future combinations of machine learning, Fourier-resolved timing, and the development of reverberation models.

Authors with CRIS profile

Thomas Dauser Dr.Karl-Remeis-Sternwarte Bamberg, Astronomisches Institut

Involved external institutions

Massachusetts Institute of Technology (MIT)

United States (USA) (US) Stanford University

United States (USA) (US) California Institute of Technology (Caltech)

United States (USA) (US) European Space Astronomy Centre (ESAC)

Spain (ES) University of Cambridge

United Kingdom (GB) University of Oxford

United Kingdom (GB) Montana State University

United States (USA) (US) National Aeronautics and Space Administration (NASA)

United States (USA) (US) University of Amsterdam

Netherlands (NL)

How to cite

APA:

Lewin, C., Kara, E., Wilkins, D., Mastroserio, G., Garcia, J.A., Zhang, R.C.,... Wang, J. (2022). X-Ray Reverberation Mapping of Ark 564 Using Gaussian Process Regression. Astrophysical Journal, 939(2). https://doi.org/10.3847/1538-4357/ac978f

MLA:

Lewin, Collin, et al. "X-Ray Reverberation Mapping of Ark 564 Using Gaussian Process Regression." Astrophysical Journal 939.2 (2022).

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