Published June 2004 | Version v1
Journal article

Catching NGC 4051 in the low state with XMM-Newton

Description

The Narrow Line Seyfert 1 (NLS 1) galaxy NGC 4051 shows unusual low flux states, lasting several months, when the 2-10 keV X-ray spectrum becomes unusually hard (photon index<1) while the spectrum at lower X-ray energies is dominated by a large soft excess. A Chandra TOO of the low state has shown that the soft excess and hard components are variable and well-correlated. The variability of the hard component rules out an origin in a distant reflector. Here we present results from a recent XMM-Newton TOO of NGC4051 in the low state, which allows a much more detailed examination of the nature of the hard and soft spectral components in the low state. We demonstrate that the spectral shape in the low state is consistent with the extrapolation of the spectral pivoting observed at higher fluxes. The XMM-Newton data also reveals the warm absorbing gas in emission, as the drop in the primary continuum flux unmasks prominent emission lines from a range of ion species

Additional details

Identifiers

DOI
10.1016/j.nuclphysbps.2004.04.043;
arXiv
arXiv:astro-ph/0309179v2;
PII
S0920563204001008;

Publishing Information

Journal Title
Nuclear Physics. B, Proceedings Supplements
Journal Volume
132
Journal Issue
1-2
Journal Page Range
p. 240-243
ISSN
0920-5632
CODEN
NPBSE7

Conference

Title
2. BeppoSAX conference on the restless high-energy universe
Dates
5-9 May 2003
Place
Amsterdam (Netherlands)

INIS

Country of Publication
Netherlands
Country of Input or Organization
International Atomic Energy Agency (IAEA)
INIS RN
36017640
Subject category
S72: PHYSICS OF ELEMENTARY PARTICLES AND FIELDS;
Resource subtype / Literary indicator
Conference
Descriptors DEI
ASTROPHYSICS; COSMIC PHOTONS; EXTRAPOLATION; HARD COMPONENT; ION EMISSION; KEV RANGE; SATELLITES; SEYFERT GALAXIES; X-RAY SPECTRA
Descriptors DEC
BOSONS; COSMIC RADIATION; ELEMENTARY PARTICLES; EMISSION; ENERGY RANGE; GALAXIES; IONIZING RADIATIONS; MASSLESS PARTICLES; MATHEMATICAL SOLUTIONS; NUMERICAL SOLUTION; PHOTONS; PHYSICS; RADIATIONS; SPECTRA

Optional Information

Copyright
Copyright (c) 2004 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.