Search Publications
Low-power radio galaxy environments in the Subaru?/XMM-Newton Deep Field at z ~ 0.5
Read, A. M.; Rawlings, S.; Geach, J. E. +2 more
We present multiobject spectroscopy of galaxies in the immediate (Mpc-scale) environments of four low-power (L1.4GHz <~ 1025 WHz-1) radio galaxies at z ~ 0.5, selected from the Subaru?/XMM-Newton Deep Field. We use the spectra to calculate velocity dispersions and central redshifts of the groups the radio galaxi…
Detection of broad 21-cm absorption at zabs = 0.656 in the complex sight-line towards 3C336
Webb, J. K.; Tzanavaris, P.; Murphy, M. T. +2 more
We report the detection of 21-cm absorption at zabs = 0.656 towards 1622 + 238 (3C336). The line is very broad with a full width to half-maximum of 235 km s-1, giving a velocity-integrated optical depth of . The centroid of the line is offset from that of the known damped Lyman α absorption system (DLA) by 50 km s-1
Is the X-ray spectrum of the narrow emission line QSO PG1211+143 defined by its energetic outflow?
Reeves, J. N.; Pounds, K. A.
An XMM-Newton observation of the bright QSO PG1211+143 in 2001 revealed a blueshifted absorption line spectrum indicative of a high-velocity radial outflow of highly ionized gas. Unless highly collimated, the outflow mass rate was shown to be comparable to the accretion rate, with mechanical energy a significant fraction of the bolometric luminosi…
A longer XMM-Newton look at I Zwicky 1: variability of the X-ray continuum, absorption and iron Kα line
Brandt, W. N.; Papadakis, I. E.; Costantini, E. +3 more
We present the second XMM-Newton observation (85 ks) of the narrow-line Seyfert 1 galaxy (NLS1) IZw1 and describe its mean spectral and timing characteristics. On average, IZw1 is ~35 per cent dimmer in 2005 than in the shorter (20ks) 2002 observation. Between the two epochs the intrinsic absorption column density diminished, but there were also s…
Separation of the visible and dark matter in the Einstein ring LBGJ213512.73-010143
Smail, Ian; Swinbank, A. M.; Edge, A. C. +2 more
We model the mass distribution in the recently discovered Einstein ring LBGJ213512.73-010143 (the `Cosmic Eye') using archival Hubble Space Telescope imaging. We reconstruct the mass density profile of the z = 0.73 lens and the surface brightness distribution of the z = 3.07 source and find that the observed ring is best fitted with a dual-compone…
The structure of the jet in 3C 15 from multiband polarimetry
Birkinshaw, M.; Worrall, D. M.; Padgett, C. A. +2 more
We investigate the structure of the kpc-scale jet in the nearby (z = 0.073) radio galaxy 3C 15, using new optical Hubble Space Telescope (HST) ACS/F606W polarimetry together with archival multiband HST imaging, Chandra X-ray data and 8.4-GHz VLA radio polarimetry. The new data confirm that synchrotron radiation dominates in the optical. With match…
A census of young stellar populations in the warm ULIRG PKS 1345+12
Tadhunter, C. N.; González Delgado, R. M.; Holt, J. +1 more
We present a detailed investigation of the young stellar populations (YSP) in the radio-loud ultraluminous infrared galaxy (ULIRG), PKS1345+12 (z = 0.12), based on high-resolution Hubble Space Telescope (HST) imaging and long-slit spectra taken with the William Herschel Telescope (WHT) at La Palma. While the images clearly show bright knots sugges…
Structure through colour: a pixel approach towards understanding galaxies
Conselice, C. J.; Lanyon-Foster, M. M.; Merrifield, M. R.
We present a study of pixel colour-magnitude diagrams (pCMDs) for a sample of 69 nearby galaxies chosen to span a wide range of Hubble types. Our goal is to determine how useful a pixel approach is for studying galaxies according to their stellar light distributions and content. The galaxy images were analysed on a pixel-by-pixel basis to reveal t…
Pre-main-sequence stars in the Lagoon Nebula (M8)*
Barbá, R. H.; Morrell, N. I.; Arias, J. I.
We report the discovery of new pre-main-sequence (PMS) stars in the Lagoon Nebula (M8) at a distance of 1.25 kpc, based on intermediate-resolution spectra obtained with the Boller & Chivens spectrograph at the 6.5-m Magellan I Telescope (Las Campanas Observatory, Chile). According to the spectral types, the presence of emission lines and the l…
Cluster and nebular properties of the central star-forming region of NGC 1140
Crowther, P. A.; Smith, L. J.; de Grijs, R. +2 more
We present new high spatial resolution Hubble Space Telescope/Advanced Camera for Surveys (ACS) imaging of NGC 1140 and high spectral resolution Very Large Telescope/Ultraviolet and Visual Echelle Spectrograph spectroscopy of its central star-forming region. The central region contains several clusters, the two brightest of which are clusters 1 an…