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Variability of the iron K-emission line in the Seyfert 1 galaxy NGC 3516

K. Nandra·R. F. Mushotzky·T. Yaqoob·I. M. George·T. J. Turner
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Abstract

We present strong evidence for variability of the flux of the iron K$α$ emission line in the Seyfert 1 galaxy, NGC 3516. Two ASCA observations, separated by $\sim 1$~yr, showed a marked decrease in continuum flux by $\sim 60$~per cent. The flux in the broad, iron K$α$ line decreased by the same factor in this time period, with no evidence for changes in the line profile. The line variability is significant at $>99$~per cent confidence and rules out models in which the line is produced in a molecular torus located at $>1$~pc from the nucleus. An accretion disk is considerably more likely.

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K. Nandra, R. F. Mushotzky, T. Yaqoob, I. M. George, T. J. Turner. 1996-08-26. Variability of the iron K-emission line in the Seyfert 1 galaxy NGC 3516. https://doi.org/10.1093/mnras%2F284.2.l7

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