Search Publications
The persistent cosmic web and its filamentary structure - II. Illustrations
Pichon, C.; Sousbie, T.; Kawahara, H.
The recently introduced discrete persistent structure extractor (DisPerSE, Sousbie, Paper I) is implemented on realistic 3D cosmological simulations and observed redshift catalogues; it is found that DisPerSE traces very well the observed filaments, walls and voids seen both in simulations and in observations. In either setting, filaments are show…
Iron line profiles in Suzaku spectra of bare Seyfert galaxies
Porquet, D.; Reeves, J. N.; Terashima, Y. +3 more
We methodically model the broad-band Suzaku spectra of a small sample of six 'bare' Seyfert galaxies: Ark 120, Fairall 9, MCG -02-14-009, Mrk 335, NGC 7469 and SWIFT J2127.4+5654. The analysis of bare Seyferts allows a consistent and physical modelling of active galactic nuclei due to a weak amount of any intrinsic warm absorption, removing the de…
A reflection origin for the soft and hard X-ray excess of Ark 120
Fabian, A. C.; Nardini, E.; Reis, R. C. +1 more
Over the last few years, several models have been proposed to interpret the widespread soft excess observed in the X-ray spectra of type 1 active galactic nuclei (AGN). In particular, reflection from the photoionized accretion disc blurred by relativistic effects has proven to be successful in reproducing both the spectral shape and the variabilit…
Multi-epoch X-ray observations of the Seyfert 1.2 galaxy Mrk 79: bulk motion of the illuminating X-ray source
Guainazzi, M.; Fabian, A. C.; Miller, J. M. +4 more
Multi-epoch X-ray spectroscopy (0.3-25 keV) of the Seyfert 1.2 galaxy Mrk 79 (UGC 3973) spanning nearly 8 yr and a factor of 3 in broad-band flux are analysed. The data are obtained at seven epochs with either XMM-Newton or Suzaku. Comparison with contemporaneous RXTE monitoring indicates that all flux states of Mrk 79 are represented by the data.…
Assessing black hole spin in deep Suzaku observations of Seyfert 1 AGN
Porquet, D.; Reeves, J. N.; Lobban, A. P. +2 more
We present a broad-band analysis of deep Suzaku observations of nearby Seyfert 1 active galactic nuclei (AGN): Fairall 9, MCG-6-30-15, NGC 3516, 3783 and 4051. The use of deep observations (exposures >200 ks) with high signal-to-noise ratio allows the complex spectra of these objects to be examined in full, taking into account features such as …
Multistate observations of the Galactic black hole XTE J1752-223: evidence for an intermediate black hole spin
Wijnands, R.; Fabian, A. C.; Miller, J. M. +6 more
The Galactic black hole candidate XTE J1752-223 was observed during the decay of its 2009 outburst with the Suzaku and XMM-Newton observatories. The observed spectra are consistent with the source being in the ‘intermediate’ and ‘low-hard’ states, respectively. The presence of a strong, relativistic iron emission line is clearly detected in both o…
Contemporaneous Chandra HETG and Suzaku X-ray observations of NGC 4051
Turner, T. J.; Kraemer, S. B.; Crenshaw, D. M. +4 more
We present the results of a deep 300 ks Chandra High Energy Transmission Grating (HETG) observation of the highly variable narrow-line Seyfert Type 1 galaxy NGC 4051. The HETG spectrum reveals 28 significant soft X-ray ionized lines in either emission or absorption; primarily originating from H-like and He-like K-shell transitions of O, Ne, Mg and…
X-ray evidence for the accretion disc-outflow connection in 3C 111
Reynolds, C. S.; Tombesi, F.; Reeves, J. N. +2 more
We present the spectral analysis of three Suzaku X-ray Imaging Spectrometer observations of 3C 111 requested to monitor the predicted variability of its ultrafast outflow on ∼7 d time-scales. We detect an ionized iron emission line in the first observation and a blueshifted absorption line in the second, when the flux is ∼30 per cent higher. The l…
Suzaku observation of the transient X-ray pulsar GRO J1008-57
Paul, Biswajit; Naik, Sachindra; Vadawale, Santosh V. +1 more
We report the timing and broad-band spectral properties of the Be transient high-mass X-ray binary pulsar GRO J1008-57 using a Suzaku observation in the declining phase of its 2007 November and December outbursts. Pulsations with a period of 93.737 s were clearly detected in the light curves of the pulsar up to the 80-100 keV energy band. The puls…
The effects of X-ray absorption variability in NGC 4395
Nardini, E.; Risaliti, G.
We present a new X-ray analysis of the dwarf Seyfert galaxy NGC 4395, based on two archival XMM-Newton and Suzaku observations. This source is well known for a series of remarkable properties: one of the smallest estimated black hole masses among active galactic nuclei (AGN) (of the order of ∼105 M⊙), intense flux variability…