Exploring the complex X-ray spectrum of NGC 4051
journal contributionposted on 2006-11-03, 13:18 authored by Kenneth A. Pounds, J.N. Reeves, Andrew R. King, Kim L. Page
Archival XMM–Newton data on the nearby Seyfert galaxy NGC 4051, taken in relatively high- and low-flux states, offer a unique opportunity to explore the complexity of its X-ray spectrum. We find the hard X-ray band to be significantly affected by reflection from cold matter, which can also explain a non-varying, narrow Fe K fluorescent line. We interpret major differences between the high- and low-flux hard X-ray spectra in terms of the varying ionization (opacity) of a substantial column of outflowing gas. An emission-line spectrum in the low-flux state indicates an extended region of photoionized gas. A high-velocity, highly ionized outflow seen in the high-flux state spectrum can replenish the gas in the extended emission region over 103 yr, while having sufficient kinetic energy to contribute significantly to the hard X-ray continuum.
CitationMonthly Notices of the Royal Astronomical Society, 2004, 350, pp.10-20
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