Search Publications
X-ray reflection in the narrow-line Seyfert 1 galaxy 1H 0707-495
Vaughan, S.; Fabian, A. C.; Boller, Th. +4 more
We apply a reflection-dominated model to the second XMM-Newton observation of the narrow-line Seyfert 1 galaxy 1H 0707-495. As in the first XMM-Newton observation, a sharp spectral drop is detected with energy that has shifted from 7 to 7.5 keV in two years. The drop is interpreted in terms of relativistically blurred ionized reflection from the a…
Analysing observed star cluster SEDs with evolutionary synthesis models: systematic uncertainties
de Grijs, R.; Anders, P.; Fritze-v. Alvensleben, U. +1 more
We discuss the systematic uncertainties inherent to analyses of observed (broad-band) spectral energy distributions (SEDs) of star clusters with evolutionary synthesis models. We investigate the effects caused by restricting oneself to a limited number of available passbands, choices of various passband combinations, finite observational errors, n…
Evidence for a multizone warm absorber in the XMM-Newton spectrum of Markarian 304
Guainazzi, M.; Schartel, N.; Rodríguez-Pascual, P. M. +3 more
We present a XMM-Newton observation of Markarian 304, a Seyfert 1 galaxy at z= 0.066. The EPIC data show that MKN 304 is affected by heavy (NH~ 1023 cm-2) obscuration arising from ionized gas. A two-phase warm absorber provides an adequate parametrization of this gas. The ionization parameter of the two components …
XMM-Newton observations of the Perseus cluster - II. Evidence for gas motions in the core
Böhringer, H.; Sunyaev, R.; Churazov, E. +2 more
The 5-9 keV spectrum of the inner ~100 kpc of the Perseus cluster measured by XMM-Newton can be well described by an optically thin plasma emission model as predicted by the APEC code, without any need for invoking a strong Ni overabundance or the effects of resonant scattering. For the strongest 6.7-keV line of He-like iron, the optical depth of …
The host galaxies of luminous quasars
Baum, Stefi A.; O'Dea, Christopher P.; Dunlop, James S. +5 more
We present the results of a deep Hubble Space Telescope (HST)/Wide Field and Planetary Camera 2 imaging study of 17 quasars at z~= 0.4, designed to determine the properties of their host galaxies. The sample consists of quasars with absolute magnitudes in the range -24 >=MV>=- 28, allowing us to investigate host galaxy properties …
The European Large-Area ISO Survey (ELAIS): the final band-merged catalogue
Elbaz, D.; Genzel, R.; Pozzi, F. +76 more
We present the final band-merged European Large-Area ISO Survey (ELAIS) Catalogue at 6.7, 15, 90 and 175 µm, and the associated data at U, g', r', i', Z, J, H, K and 20 cm. The origin of the survey, infrared and radio observations, data-reduction and optical identifications are briefly reviewed, and a summary of the area covered and the comp…
An X-ray Baldwin effect for the narrow Fe Kα lines observed in active galactic nuclei
O'Brien, P. T.; Reeves, J. N.; Page, K. L. +1 more
The majority of active galactic nuclei (AGN) observed by XMM-Newton reveal narrow Fe Kα lines at ~6.4 keV, due to emission from cold (neutral) material. There is an X-ray Baldwin effect in type I AGN, in that the equivalent width (EW) of the line decreases with increasing luminosity, with weighted linear regression giving EW~L-0.17+/-0.08
Lithium abundances of the local thin disc stars
Lambert, David L.; Reddy, Bacham E.
Lithium abundances are presented for a sample of 181 nearby F and G dwarfs with accurate Hipparcos parallaxes. The stars are on circular orbits about the Galactic centre and, hence, are identified as belonging to the thin disc. This sample is combined with two published surveys to provide a catalogue of lithium abundances, metallicities ([Fe/H]), …
Flux and energy modulation of redshifted iron emission in NGC 3516: implications for the black hole mass
Iwasawa, K.; Fabian, A. C.; Miniutti, G.
We report on the tentative detection of the modulation of a transient, redshifted Fe Kα emission feature in the X-ray spectrum of the Seyfert galaxy NGC 3516. The detection of the spectral feature at 6.1 keV, in addition to a stable 6.4-keV line, has been reported previously. We find, on reanalysing the XMM-Newton data, that the feature varies sys…
A sample of radio galaxies spanning three decades in radio luminosity - I. The host galaxy properties and black hole masses
Willott, Chris J.; Rawlings, Steve; Jarvis, Matt J. +5 more
The results of analysis of HST I-band imaging of a sample of 41 radio galaxies spanning three orders of magnitude in radio luminosity at redshift z~= 0.5 are presented. These results represent the first stage in a coordinated programme to study the connection between radio luminosity and host galaxy properties, black hole masses and cluster enviro…