Search Publications
A serendipitous XMM survey of the SDSS: the evolution of the colour-magnitude diagram of X-ray AGN from z= 0.8 to 0.1
Nandra, K.; Georgakakis, Antonis
A new serendipitous XMM survey in the area of the Sloan Digital Sky Survey is described (XMM/SDSS), which includes features such as merging of overlapping fields to increase the sensitivity to faint sources, use of a new parametrization of the XMM point spread function for the source detection and photometry and an accurate estimation of the surve…
Constraining the star formation and the assembly histories of normal and compact early-type galaxies at 1 < z < 2
Longhetti, M.; Gargiulo, A.; Saracco, P.
We present a study based on a sample of 62 early-type galaxies (ETGs) at 0.9 < zspec < 2 aimed at constraining their past star formation and mass assembly histories. The sample is composed of normal ETGs having effective radii comparable to the mean radius of local ones and of compact ETGs having effective radii from two to six ti…
Precision cosmology with a wide area XMM cluster survey
Pierre, M.; Clerc, N.; Pacaud, F. +4 more
We explore the cosmological constraints expected from wide area XMM-type cluster surveys covering 50-200 deg2, under realistic observing conditions. We perform a Fisher matrix analysis, based on cluster number counts in combination with estimates of the two-point cluster correlation function. The effect of the survey design is implement…
The winds of hydrogen-rich central stars of planetary nebulae
Bianchi, L.; Herald, J. E.
We have modelled far-UV, UV and optical spectra of a sample of 10 hydrogen-rich central stars of planetary nebulae (CSPN) using stellar atmosphere codes to derive their photospheric and wind parameters. The resulting stellar temperatures range from 40 to 120 kK, well spanning the CSPN evolutionary phase and allowing certain trends to be discerned.…
The extremely high velocity outflow in quasar PG0935+417
Hamann, Fred; Hall, Patrick; Rodríguez Hidalgo, Paola
We report the detection of O VI λλ1031, 1037 and N V λλ1238, 1242 absorption in a system of ‘mini-broad' absorption lines (mini-BALs) previously reported to have variable C IV λλ1548, 1550 in the quasar PG0935+417. The formation of these lines in an extremely high velocity outflow (with v∼-50 000 km s-1) is confirmed by the line variabi…
A SINFONI view of flies in the Spiderweb: a galaxy cluster in the making
Pentericci, L.; Röttgering, H. J. A.; Miley, G. K. +8 more
The environment of the high-z radio galaxy PKS 1138-262 at z∼ 2.2 is a prime example of a forming galaxy cluster. We use deep Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) integral field spectroscopy to perform a detailed study of the kinematics of the galaxies within 60 kpc of the radio core and we link this to the k…
The star formation history in the far outer disc of M33
Cole, A. A.; Tanvir, N. R.; Ferguson, A. M. N. +5 more
The outer regions of disc galaxies are becoming increasingly recognized as key testing sites for models of disc assembly and evolution. Important issues are the epoch at which the bulk of the stars in these regions formed and how discs grow radially over time. To address these issues, we use Hubble Space Telescope Advanced Camera for Surveys imagi…
X-ray reverberation close to the black hole in RE J1034+396
Fabian, A. C.; Zoghbi, A.
In previous work, we discussed the detection of reverberation delays in the narrow-line Seyfert 1 (NLS1) 1H0707-495. The delays originate close to the black hole. Here, we show that RE J1034+396 shows very similar lag properties. At low frequencies (<1 × 10-4 Hz), the time lag between energy bands increases with energy separation, si…
A near-infrared morphological comparison of high-redshift submillimetre and radio galaxies: massive star-forming discs versus relaxed spheroids
Almaini, Omar; Dunlop, James S.; McLure, Ross J. +3 more
We present deep, high-quality K-band images of complete subsamples of powerful radio and submillimetre galaxies at redshifts z≃ 2. The data were obtained in the very best available seeing via queue-based observations at the United Kingdom Infrared Telescope and Gemini-North, with integration times scaled to ensure that comparable rest-frame surfac…
X-ray spectral evolution in the ultraluminous X-ray source M33 X-8
Middleton, Matthew J.; Sutton, Andrew D.; Roberts, Timothy P.
The bright ultraluminous X-ray source (ULX), M33 X-8, has been observed several times by XMM-Newton, providing us with a rare opportunity to 'flux bin' the spectral data and search for changes in the average X-ray spectrum with flux level. The aggregated X-ray spectra appear unlike standard sub-Eddington accretion state spectra which, alongside th…