Search Publications
Chandra unveils a binary active galactic nucleus in Mrk 463
Guainazzi, Matteo; Bianchi, Stefano; Piconcelli, Enrico +2 more
We analyse Chandra, XMM-Newton and Hubble Space Telescope (HST) data of the double-nucleus Ultraluminous Infrared Galaxy (ULIRG), Mrk 463. The Chandra detection of two luminous (L2-10keV = 1.5 × 1043 and 3.8 × 1042 erg cm-2 s-1), unresolved nuclei in Mrk 463 indicates that this galaxy hosts a …
On why the iron K-shell absorption in AGN is not a signature of the local warm/hot intergalactic medium
Done, Chris; Terashima, Yuichi; Hayashida, Kiyoshi +5 more
We present a comparison between the 2001 XMM-Newton and 2005 Suzaku observations of the quasar, PG1211+143, at z = 0.0809. Variability is observed in the 7 keV iron K-shell absorption line (at 7.6 keV in the quasar frame), which is significantly weaker in 2005 than during the 2001 XMM-Newton observation. From a recombination time-scale of <4 yr…
Constraints on decaying dark matter from XMM-Newton observations of M31
Boyarsky, Alexey; Ruchayskiy, Oleg; Iakubovskyi, Dmytro +1 more
We derive constraints on the parameters of the radiatively decaying dark matter (DM) particle, using the XMM-Newton EPIC spectra of the Andromeda galaxy (M31). Using the observations of the outer (5-13arcmin) parts of M31, we improve the existing constraints. For the case of sterile neutrino DM, combining our constraints with the latest computatio…
A systematic look at the very high and low/hard state of GX339-4: constraining the black hole spin with a new reflection model
Fabian, A. C.; Miller, J. M.; Miniutti, G. +3 more
We present a systematic study of GX 339-4 in both its very high and low hard states from simultaneous observations made with XMM-Newton and RXTE in 2002 and 2004. The X-ray spectra of both these extreme states exhibit strong reflection signatures, with a broad, skewed Fe Kα line clearly visible above the continuum. Using a newly developed, self-co…
An XMM-Newton study of the environments, particle content and impact of low-power radio galaxies
Hardcastle, M. J.; Croston, J. H.; Birkinshaw, M. +2 more
We present a detailed study of the environments of a sample of nine low-power [Fanaroff-Riley type I (FRI)] radio galaxies, based on new and archival XMM-Newton observations. We report new detections of group-scale environments around three radio galaxies: 3C296, NGC1044 and 3C76.1. As with previous studies, we find that FRI radio galaxies inhabit…
X-ray spectra from magnetar candidates - I. Monte Carlo simulations in the non-relativistic regime
Zane, S.; Nobili, L.; Turolla, R.
The anomalous X-ray pulsars (AXPs) and soft γ-repeaters (SGRs) are peculiar high-energy sources believed to host a magnetar, an ultramagnetized neutron star with surface magnetic field in the petagauss range. Their persistent, soft X-ray emission exhibits a two component spectrum, usually modelled by the superposition of a blackbody and a power-la…
Multidimensional modelling of X-ray spectra for AGN accretion disc outflows
Turner, T. J.; Long, K. S.; Sim, S. A. +1 more
We use a multidimensional Monte Carlo code to compute X-ray spectra for a variety of active galactic nucleus (AGN) disc-wind outflow geometries. We focus on the formation of blueshifted absorption features in the Fe K band and show that line features similar to those which have been reported in observations are often produced for lines of sight th…
Galaxy evolution in Hickson compact groups: the role of ram-pressure stripping and strangulation
Yun, Min S.; Ponman, Trevor J.; Verdes-Montenegro, Lourdes +2 more
Galaxies in compact groups tend to be deficient in neutral hydrogen compared to isolated galaxies of similar optical properties. In order to investigate the role played by a hot intragroup medium (IGM) for the removal and destruction of HI in these systems, we have performed a Chandra and XMM-Newton study of eight of the most HI deficient Hickson …
A deep X-ray observation of M82 with XMM-Newton
Maiolino, R.; Ranalli, P.; Comastri, A. +1 more
We report on the analysis of a deep (100-ks) observation of the starburst galaxy M82 with the EPIC and RGS instruments onboard the X-ray telescope XMM-Newton. The broad-band (0.5-10 keV) emission is due to at least three spectral components: (i) continuum emission from point sources; (ii) thermal plasma emission from hot gas; and (iii) charge-exch…
Cool X-ray emitting gas in the core of the Centaurus cluster of galaxies
Fabian, A. C.; Allen, S. W.; Sanders, J. S. +3 more
We use a deep XMM-Newton Reflection Grating Spectrometer observation to examine the X-ray emission from the core of the Centaurus cluster of galaxies. We clearly detect FeXVII emission at four separate wavelengths, indicating the presence of cool X-ray emitting gas in the core of the cluster. Fe ions from FeXVII toXXIV are observed. The ratio of t…