Search Publications
The XMM-Newton view of Mrk 3 and IXO 30
Fabian, Andrew C.; Bianchi, Stefano; Miniutti, Giovanni +1 more
We present the analysis of the XMM-Newton European Photon Imaging Camera (EPIC) pn spectrum of the Seyfert 2 galaxy Mrk 3. We confirm that the source is dominated by a pure Compton reflection component and an iron Kα line, both produced as a reflection from a Compton-thick torus, likely responsible also for the large column density (1.36+0.03…
High-mass X-ray binaries in the Small Magellanic Cloud: the luminosity function
Gilfanov, M.; Shtykovskiy, P.
We study a population of compact X-ray sources in the Small Magellanic Cloud (SMC) using archival data from the XMM-Newton observatory. The total area of the survey is ~1.5 deg2 with the limiting sensitivity of ~10-14 erg s-1 cm-2, corresponding to a luminosity of ~4.3 × 1033 erg s-1
Hubble Space Telescope ultraviolet spectroscopy of blazars: emission-line properties and black hole masses
Pian, E.; Falomo, R.; Treves, A.
The ultraviolet (UV) spectra of 16 blazars (<z>~= 1) from the archives of the Hubble Space Telescope Faint Object Spectrograph have been analysed in order to study in a systematic way the properties of their broad UV emission lines. We find that the luminosities of the most prominent and intense lines, Lyα and CIVλ1549, are similar to those …
On the transmission-dominated to reprocessing-dominated spectral state transitions in Seyfert 2 galaxies
Fiore, F.; Guainazzi, M.; Iwasawa, K. +2 more
We present Chandra and XMM-Newton observations of a small sample (11 objects) of optically selected Seyfert 2 galaxies, for which ASCA and BeppoSAX had suggested Compton-thick obscuration of the active galactic nucleus (AGN). The main goal of this study is to estimate the rate of transitions between `transmission-dominated' and `reprocessing-domin…
Evidence for radio-source heating of groups
Hardcastle, M. J.; Croston, J. H.; Birkinshaw, M.
We report evidence that the gas properties of X-ray groups containing radio galaxies differ from those of radio-quiet groups. For a well-studied sample of ROSAT-observed groups, we found that more than half of the elliptical-dominated groups can be considered `radio-loud', and that radio-loud groups are likely to be hotter at a given X-ray luminos…
The Chandra view of extended X-ray emission from Pictor A
Hardcastle, M. J.; Croston, J. H.
We discuss the extended X-ray emission seen in three archival Chandra observations, and one archival XMM-Newton observation, of the Fanaroff-Riley type II radio galaxy, Pictor A. The overall properties of the X-ray lobes are consistent with the conclusions of earlier works that the extended X-ray emission is largely due to the inverse-Compton proc…
The exceptional X-ray variability of the dwarf Seyfert nucleus NGC 4395
Iwasawa, K.; Vaughan, S.; Fabian, A. C. +1 more
An analysis of the X-ray variability of the low-luminosity Seyfert nucleus NGC 4395, based on a long XMM-Newton observation, is presented. The power spectrum shows a clear break from a flat spectrum (α~ 1) to a steeper spectrum (α~ 2) at a frequency fbr= 0.5-3.0 × 10-3 Hz, comparable to the highest characteristic frequency fo…
The first detection of [OIII] emission from high-redshift damped Lyman-α galaxies
Fall, S. M.; Møller, P.; Weatherley, S. J. +3 more
We present the detection of [OIII] emission lines from the galaxies responsible for two high-redshift z > 1.75 damped Lyman-α (DLA) absorption lines. We find two sources of [OIII] emission corresponding to the z= 1.92 DLA absorber towards the quasar Q2206-1958, and we also detect [OIII] emission from the galaxy responsible for the z= 3.10 DLA a…
Pushing the ground-based limit: 14-µmag photometric precision with the definitive Whole Earth Telescope asteroseismic data set for the rapidly oscillating Ap star HR1217
Kepler, S. O.; Kawaler, S. D.; Winget, D. E. +43 more
HR1217 is one of the best-studied rapidly oscillating Ap (roAp) stars, with a frequency spectrum of alternating even- and odd-l modes that are distorted by the presence of a strong, global magnetic field. Several recent theoretical studies have found that within the observable atmospheres of roAp stars the pulsation modes are magneto-acoustic with…
Non-parametric mass reconstruction of A1689 from strong lensing data with the Strong Lensing Analysis Package
Diego, J. M.; Broadhurst, T.; Benítez, N. +3 more
We present the mass distribution in the central area of the cluster A1689 by fitting over 100 multiply lensed images with the non-parametric Strong Lensing Analysis Package. The surface mass distribution is obtained in a robust way, finding a total mass of 0.25 × 1015h-1 Msolar within a 70-arcsec circle radius from…