Search Publications
Suzaku observations of `bare' active galactic nuclei
Fabian, A. C.; Nardini, E.; Reis, R. C. +2 more
We present an X-ray spectral analysis of a large sample of 25 `bare' active galactic nuclei (AGN), sources with little or no complicating intrinsic absorption, observed with Suzaku. Our work focuses on studying the potential contribution from relativistic disc reflection and examining the implications of this interpretation for the intrinsic spect…
The Suzaku view of highly ionized outflows in AGN - I. Statistical detection and global absorber properties
Reeves, James N.; Tombesi, Francesco; Miller, Lance +4 more
We present the results of a new spectroscopic study of Fe K-band absorption in active galactic nuclei (AGN). Using data obtained from the Suzaku public archive we have performed a statistically driven blind search for Fe XXV Heα and/or Fe XXVI Lyα absorption lines in a large sample of 51 Type 1.0-1.9 AGN. Through extensive Monte Carlo simulations …
Properties of gas clumps and gas clumping factor in the intra-cluster medium
Simionescu, A.; Eckert, D.; Ettori, S. +2 more
The spatial distribution of gas matter inside galaxy clusters is not completely smooth, but may host gas clumps associated with substructures. These overdense gas substructures are generally a source of unresolved bias of X-ray observations towards high-density gas, but their bright luminosity peaks may be resolved sources within the intra cluster…
Measurements and simulation of Faraday rotation across the Coma radio relic
Vazza, F.; Bonafede, A.; Govoni, F. +5 more
The aim of this work is to probe the magnetic field properties in relics and infall regions of galaxy clusters using Faraday rotation measures. We present Very Large Array multifrequency observations of seven sources in the region south-west of the Coma cluster, where the infalling group NGC 4839 and the relic 1253+275 are located. The Faraday rot…
X-ray exploration of the outskirts of the nearby Centaurus cluster using Suzaku and Chandra
Simionescu, A.; Fabian, A. C.; Sanders, J. S. +2 more
We present Suzaku observations of the Centaurus cluster out to 0.95r200, taken along a strip to the north-west. We have also used congruent Chandra observations of the outskirts to resolve point sources down to a threshold flux around seven times lower than that achievable with just Suzaku data, considerably reducing the systematic unce…
An examination of the spectral variability in NGC 1365 with Suzaku
Elvis, M.; Nardini, E.; Brenneman, L. W. +1 more
We present jointly analysed data from three deep Suzaku observations of NGC 1365. These high-signal-to-noise spectra enable us to examine the nature of this variable, obscured active galactic nucleus (AGN) in unprecedented detail on time-scales ranging from hours to years. We find that in addition to the power-law continuum and absorption from ion…
On the nature of the hard X-ray sources SWIFT J1907.3-2050, IGR J12123-5802 and IGR J19552+0044
Mukai, K.; de Martino, D.; Masetti, N. +7 more
The INTEGRAL and Swift hard X-ray surveys have identified a large number of new sources, among which many are proposed as Cataclysmic Variables (CVs). Here, we present the first detailed study of three X-ray-selected CVs, Swift J1907.3-2050, IGR J12123-5802 and IGR J19552+0044 based on XMM-Newton, Suzaku, Swift observations and ground-based optica…
A Suzaku X-ray observation of one orbit of the supergiant fast X-ray transient IGR J16479-4514
Tomsick, J. A.; Rodriguez, J.; Sidoli, L. +6 more
We report on a 250 ks long X-ray observation of the supergiant fast X-ray transient IGR J16479-4514 performed with Suzaku in 2012 February. During this observation, about 80 per cent of the short orbital period (Porb ∼ 3.32 d) was covered as continuously as possible for the first time. The source light curve displays variability of more…
1ES 1927+654: a bare Seyfert 2
Fabian, A. C.; Cackett, E. M.; Panessa, F. +3 more
1ES 1927+654 is an active galactic nucleus (AGN) that appears to defy the unification model. It exhibits a type-2 optical spectrum, but possesses little X-ray obscuration. XMM-Newton and Suzaku observations obtained in 2011 are used to study the X-ray properties of 1ES 1927+654. The spectral energy distribution derived from simultaneous optical-to…
Decoupling absorption and continuum variability in the Seyfert 2 NGC 4507
Ptak, A.; Turner, T. J.; Ballo, L. +3 more
We present the results of the Suzaku observation of the Seyfert 2 galaxy NGC 4507. This source is one of the X-ray brightest Compton-thin Seyfert 2s and a candidate for a variable absorber. Suzaku caught NGC 4507 in a highly absorbed state characterized by a high column density (NH ∼ 8 × 1023 cm-2), a strong reflec…