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arXiv · 1208.5898

Long XMM observation of the Narrow-Line Seyfert 1 galaxy IRAS13224-3809: rapid variability, high spin and a soft lag

A. C. Fabian·E. Kara·D. J. Walton·D. R. Wilkins·R. R. Ross·K. Lozanov·P. Uttley·L. C. Gallo·A. Zoghbi·G. Miniutti·T. Boller·W. N. Brandt·E. M. Cackett·C. -Y. Chiang·T. Dwelly·J. Malzac·J. M. Miller·E. Nardini·G. Ponti·R. C. Reis·C. S. Reynolds·J. Steiner·Y. Tanaka·A. J. Young
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Abstract

Results are presented from a 500ks long XMM-Newton observation of the Narrow-Line Seyfert 1 galaxy IRAS13224-3809. The source is rapidly variable on timescales down to a few 100s. The spectrum shows strong broad Fe-K and L emission features which are interpreted as arising from reflection from the inner parts of an accretion disc around a rapidly spinning black hole. Assuming a power-law emissivity for the reflected flux and that the innermost radius corresponds to the innermost stable circular orbit, the black hole spin is measured to be 0.988 with a statistical precision better than one per cent. Systematic uncertainties are discussed. A soft X-ray lag of 100s confirms this scenario. The bulk of the power-law continuum source is located at a radius of 2-3 gravitational radii.

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A. C. Fabian, E. Kara, D. J. Walton, D. R. Wilkins, R. R. Ross, K. Lozanov, P. Uttley, L. C. Gallo, A. Zoghbi, G. Miniutti, T. Boller, W. N. Brandt, E. M. Cackett, C. -Y. Chiang, T. Dwelly, J. Malzac, J. M. Miller, E. Nardini, G. Ponti, R. C. Reis, C. S. Reynolds, J. Steiner, Y. Tanaka, A. J. Young. 2012-08-29. Long XMM observation of the Narrow-Line Seyfert 1 galaxy IRAS13224-3809: rapid variability, high spin and a soft lag. https://doi.org/10.1093/mnras/sts504

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