Search Publications
A Chandra and XMM-Newton study of the wide-angle tail radio galaxy 3C465
Hardcastle, M. J.; Worrall, D. M.; Sakelliou, I.
We have observed the prototypical wide-angle tail (WAT) radio galaxy 3C465 with Chandra and XMM-Newton. X-ray emission is detected from the active nucleus and the inner radio jet, as well as a small-scale, cool component of thermal emission, a number of the individual galaxies of the host cluster (Abell 2634), and the hotter thermal emission from …
A bar signature and central disc in the gaseous and stellar velocity fields of NGC 5448
Emsellem, Eric; van de Ven, Glenn; Peletier, Reynier F. +4 more
We analyse Spectrographic Areal Unit for Research on Optical Nebulae (SAURON) kinematic maps of the inner kiloparsec of the early-type (Sa) barred spiral galaxy NGC 5448. The observed morphology and kinematics of the emission-line gas is patchy and perturbed, indicating clear departures from circular motion. The kinematics of the stars is more reg…
An XMM-Newton observation of Mkn 3 - a Seyfert galaxy just over the edge
Page, K. L.; Pounds, K. A.
A 100-ks XMM-Newton observation of the nearby Seyfert 2 galaxy Mkn 3 offers a unique opportunity to explore the complexity of its X-ray spectrum. We find the ~3-8 keV continuum to be dominated by reflection from cold matter, with fluorescent K-shell lines detected from Ni, Fe, Ca, Ar, S, Si and Mg. At higher energies an intrinsic power-law continu…
Supermassive black hole mass measurements for NGC 1300 and 2748 based on Hubble Space Telescope emission-line gas kinematics
Marconi, A.; Capetti, A.; Carollo, C. M. +18 more
We present Space Telescope Imaging Spectrograph emission-line spectra of the central regions of the spiral galaxies NGC 1300 and 2748. From the derived kinematics of the nuclear gas we have found evidence for central supermassive black holes in both galaxies. The estimated masses of the black holes in NGC 1300 and 2748 are (6.6+6.3…
A deep survey of brown dwarfs in Orion with Gemini
Tamura, M.; Lucas, P. W.; Roche, P. F.
We report the results of a deep near-infrared (JHK) survey of the outer parts of the Trapezium Cluster with Gemini South/Flamingos. 396 sources were detected in a 26 arcmin2 area, including 138 brown dwarf candidates, defined as M < 0.075 Msolar for an assumed age of 1 Myr. Only 33 of the brown dwarf candidates are planeta…
Self-regulated active galactic nuclei heating in elliptical galaxies
Kawata, D.; Gibson, B. K.
We study the effect of active galactic nuclei (AGN) heating on the chemodynamical evolution of elliptical galaxies and their X-ray and optical properties using high-resolution Λ-dominated cold dark matter cosmological simulations. Our model considers an AGN as being `active' when a convergent gas inflow condition exists within the nucleus of a gal…
Where are the X-ray quasi-periodic oscillations in active galaxies?
Vaughan, S.; Uttley, P.
In this paper, we address the question of whether existing X-ray observations of Seyfert galaxies are sufficiently sensitive to detect quasi-periodic oscillations (QPOs) similar to those observed in the X-ray variations of Galactic black holes (GBHs). We use data from XMM-Newton and simulated data based on the best Rossi X-ray Timing Explorer (RXT…
The X-ray emission properties and the dichotomy in the central stellar cusp shapes of early-type galaxies
Pellegrini, S.
The Hubble Space Telescope has revealed a dichotomy in the central surface brightness profiles of early-type galaxies, which have subsequently been grouped into two families: core, boxy, anisotropic systems; and cuspy (`power-law'), discy, rotating ones. Here we investigate whether a dichotomy is also present in the X-ray properties of the two fam…
Stellar populations and Lyα emission in two lensed z>~ 6 galaxies
Schaerer, Daniel; Pelló, Roser
We present an analysis of two strongly lensed galaxies at z= 6.56 and z~ 7 for which multi-band photometric and spectroscopic observations are available. For one source, the data include recent Hubble Space Telescope (HST) and Spitzer observations. Using a spectral energy distribution (SED) fitting technique considering a number of parameters (var…
Dust in spiral galaxies: global properties
Stevens, J. A.; Gear, W. K.; Amure, M.
We present and analyse high-quality Submillimetre Common-User Bolometer Array (SCUBA) 850- and 450-µm images of 14 local spiral galaxies, including the detection of dust well out into the extended disc in many cases. We use these data in conjunction with published far-infrared flux densities from IRAS and ISO, and millimetre-wave measurement…