Search Publications
Herschel-ATLAS: modelling the first strong gravitational lenses
Ivison, R. J.; Smith, M.; Cooray, A. +14 more
We have determined the mass density radial profiles of the first five strong gravitational lens systems discovered by the Herschel Astrophysical Terahertz Large Area Survey. We present an enhancement of the semilinear lens inversion method of Warren & Dye which allows simultaneous reconstruction of several different wavebands and apply this to…
Constraints on the merging channel of massive galaxies since z ∼ 1
Hernán-Caballero, A.; Cava, A.; Pérez-González, P. G. +8 more
We probe the merging channel of massive galaxies over the z = 0.3-1.3 redshift window by studying close pairs in a sample of 238 galaxies with stellar mass ≳1011 M⊙, from the SHARDS (Survey for High-z Absorption Red and Dead Sources) survey. SHARDS provides medium-band photometry equivalent to low-resolution optical spectra (…
Two estimates of the distance to the Galactic Centre
Francis, Charles; Anderson, Erik
We use recently updated globular cluster distances to estimate the distance to the Galactic Centre, finding 7.4 ± 0.2|stat ± 0.2|sys kpc from symmetry considerations, including a trough at the Galactic Centre and peaks denoting the position of the bar. We recalibrate the red clump magnitude from Hipparcos stars, finding a ske…
Gas inflows towards the nucleus of the active galaxy NGC 7213
Schnorr-Müller, Allan; Storchi-Bergmann, Thaisa; Nagar, Neil M. +1 more
We present two-dimensional stellar and gaseous kinematics of the inner 0.8 × 1.1 kpc2 of the LINER/Seyfert 1 galaxy NGC 7213, from optical spectra obtained with the Gemini Multi-Object Spectrograph integral field spectrograph on the Gemini South telescope at a spatial resolution of ≈ 60 pc. The stellar kinematics shows an average veloci…
A volume-limited sample of X-ray galaxy groups and clusters - II. X-ray cavity dynamics
Fabian, A. C.; Hlavacek-Larrondo, J.; Sanders, J. S. +1 more
We present the results of our study of a volume-limited sample (z ≤ 0.071) of 101 X-ray galaxy groups and clusters, in which we explore the X-ray cavity energetics. Out of the 101 sources in our parent sample, X-ray cavities are found in 30 of them, all of which have a central cooling time of ≤3 Gyr. New X-ray cavities are detected in three source…
Alignment in star-debris disc systems seen by Herschel
Olofsson, G.; Duchêne, G.; Eiroa, C. +28 more
Many nearby main-sequence stars have been searched for debris using the far-infrared Herschel satellite, within the DEBRIS, DUNES and Guaranteed-Time Key Projects. We discuss here 11 stars of spectral types A-M where the stellar inclination is known and can be compared to that of the spatially resolved dust belts. The discs are found to be well al…
Black hole accretion preferentially occurs in gas-rich galaxies*
Lutz, D.; Maiolino, R.; Pozzi, F. +15 more
We have investigated the gas content of a sample of several hundred AGN host galaxies at z < 1 and compared it with a sample of inactive galaxies, matched in bins of stellar mass and redshift. Gas masses have been inferred from the dust masses, obtained by stacked Herschel far-IR and sub-mm data in the GOODS and COSMOS fields, under reasonable …
Detection of a QPO in five XMM-Newton observations of RE J1034+396.
Fabian, A. C.; Kara, E.; Alston, W. N. +2 more
The X-ray quasi-periodic oscillation (QPO) at ∼2.6 × 10-4 Hz in RE J1034+396 has been robustly observed in the 0.2-10 keV band of one ∼90 ks XMM-Newton observation, but was not detected in subsequent observations. Here, we investigate the power spectral density (PSD) of eight archival XMM-Newton observations of RE J1034+396, and search …
Found: the progenitors of AM CVn and supernovae .Ia
Hermes, J. J.; Bell, Keaton J.; Gianninas, A. +7 more
We present optical and X-ray observations of two tidally distorted, extremely low-mass white dwarfs (WDs) with massive companions. There is no evidence of neutron stars in our Chandra and XMM observations of these objects. SDSS J075141.18-014120.9 (J0751) is an eclipsing double WD binary containing a 0.19 M⊙ WD with a 0.97 M⊙…
Exploiting the full potential of photometric quasar surveys: optimal power spectra through blind mitigation of systematics
Leistedt, Boris; Peiris, Hiranya V.
We present optimal measurements of the angular power spectrum of the XDQSOz catalogue of photometric quasars from the Sloan Digital Sky Survey. These measurements rely on a quadratic maximum likelihood estimator that simultaneously measures the auto- and cross-power spectra of four redshift samples, and provides minimum-variance, unbiased estimate…