Search Publications
The nature of the HE0450-2958 system
Robinson, Andrew; Storchi-Bergmann, Thaisa; Merritt, David +3 more
Magain et al. argued that the host galaxy of the quasar in HE0450-2958 is substantially underluminous given the quasar brightness. Using kinematical information from the spectra of the quasar and the companion galaxy, an ultraluminous infrared galaxy, we test the hypothesis that the black hole powering the quasar was ejected from the companion gal…
Shapley Optical Survey - II. The effect of environment on the colour-magnitude relation and galaxy colours
Mercurio, A.; Capaccioli, M.; Gargiulo, A. +5 more
We present an analysis of the effects of environment on the photometric properties of galaxies in the core of the Shapley supercluster at z = 0.05, one of the most massive structures in the local universe. The Shapley Optical Survey (SOS) comprises archive Wide Field Imager (WFI) optical imaging of a 2.0deg2 region containing the rich c…
A fossil galaxy cluster: an X-ray and optical study of RX J1416.4+2315
Ponman, Trevor J.; Khosroshahi, Habib G.; Maughan, Ben J. +1 more
We present a detailed X-ray and optical study of a distant fossil system RX J1416.4+2315(z ~ 0.137), combining Chandra and XMM-Newton observations, optical photometry and spectroscopy. X-ray emitting hot gas imaged by both the Chandra and XMM-Newton shows a globally relaxed spatial distribution, supporting the idea that fossil groups are old galax…
The planetary nebula population of the Sagittarius dwarf spheroidal galaxy
Minniti, D.; Walsh, J. R.; van Hoof, P. A. M. +3 more
The identification of two new planetary nebulae (PNe) in the Sagittarius dwarf spheroidal galaxy (Sgr) is presented. This brings the total number to four. Both new PNe were previously classified as Galactic objects. The first, StWr 2-21, belongs to the main body of Sgr, from its velocity and location. The second, the halo PN BoBn1, has a location,…
XMM-LSS discovery of a z = 1.22 galaxy cluster
Altieri, B.; Valtchanov, I.; Surace, J. A. +11 more
We present details of the discovery of XLSS J022303.0-043622, a z = 1.2 cluster of galaxies. This cluster was identified from its X-ray properties and selected as a z > 1 candidate from its optical/near-infrared (IR) characteristics in the XMM Large-Scale Structure Survey (XMM-LSS). It is the most distant system discovered in the survey to date…
The X-ray properties of young radio-loud AGN
Vink, Jacco; Snellen, Ignas; Mack, Karl-Heinz +1 more
We present XMM-Newton observations of a complete sample of five archetypal young radio-loud active galactic nucleus (AGN), also known as Compact Symmetric Objects (CSO) or Gigahertz Peaked Spectrum (GPS) sources. They are among the brightest and best studied GPS/CSO sources in the sky, with radio powers in the range L5GHz= 1043-44<…
A variable Quasi-Periodic Oscillation in M82 X-1. Timing and spectral analysis of XMM-Newton and RossiXTE observations
Belloni, T.; Ranalli, P.; Casella, P. +2 more
We report results from a spectral and timing analysis of M82 X-1, one of the brightest known ultraluminous X-ray sources. Data from a new 105-ks XMM-Newton observation of M82 X-1, performed in 2004 April, and of archival RossiXTE observations are presented. A very soft thermal component is present in the XMM spectrum. Although it is not possible t…
The distribution of absorption in AGN detected in the XMM-Newton observations of the CDFS
Page, M. J.; Dwelly, T.
We have used very deep XMM-Newton observations of the Chandra Deep Field-South to examine the spectral properties of the faint active galactic nucleus (AGN) population. Crucially, redshift measurements are available for 84 per cent (259/309) of the XMM-Newton sample. We have calculated the absorption and intrinsic luminosities of the sample using …
XMM-Newton observations of the massive colliding wind binary and non-thermal radio emitter CygOB2#8A [O6If + O5.5III(f)]
Blomme, R.; Rauw, G.; De Becker, M. +5 more
We report on the results of four XMM-Newton observations separated by about ten days from each other of CygOB2#8A [O6If + O5.5III(f)]. This massive colliding wind binary is a very bright X-ray emitter - one of the first X-ray emitting O-stars discovered by the Einstein satellite - as well as a confirmed non-thermal radio emitter whose binarity was…
The build-up of the red sequence in the galaxy cluster MS1054-0321 at z = 0.831
Andreon, S.
Using one of the deepest data sets available, we determine that the red sequence of the massive cluster MS1054-0321 at z = 0.831 is well populated at all studied magnitudes, showing no deficit of faint (down to M* + 3.5) red galaxies: the faint end of the colour-magnitude relation is neither empty nor underpopulated. The effect is quantified by th…