Rapidly variable Fe K$α$ line in NGC 4051

J. X. Wang; Y. Y. Zhou; H. G. Xu; T. G. Wang

doi:10.1086/312004

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arXiv · astro-ph/9904321

Rapidly variable Fe K$α$ line in NGC 4051

J. X. Wang·Y. Y. Zhou·H. G. Xu·T. G. Wang

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Abstract

We present a detailed analysis on the variability of the Fe K emission line in NGC 4051 using ASCA data. Through simple Gaussian line fits, we find not only obvious Fe K line variability with no significant difference in the X-ray continuum flux between two ASCA observations which were separated by $\sim$ 440 days, but also rapid variability of Fe K line on time scales $\sim 10^4$ s within the second observation. During the second observation, the line is strong (EW = 733$^{+206}_{-219}$ eV) and broad ($σ= 0.96^{+0.49}_{-0.35}$ keV) when the source is brightest, and become weaker (EW = 165$^{+87}_{-86}$ eV) and narrower ($σ<0.09$ keV) whilst the source is weakest. The equivalent width of Fe K line correlates positively with the continuum flux, which shows an opposite trend with another Seyfert 1 galaxy MCG --6-30-15.

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J. X. Wang, Y. Y. Zhou, H. G. Xu, T. G. Wang. 1999-04-23. Rapidly variable Fe K$α$ line in NGC 4051. https://doi.org/10.1086/312004

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