Search Publications
Serendipitous active galactic nuclei in the XMM-Newton fields of Markarian 205 and QSO 0130-403
O'Brien, P. T.; Reeves, J. N.; Page, K. L. +2 more
The X-ray spectra of serendipitously observed active galactic nuclei (AGN) in the XMM-Newton fields of Mrk 205 and QSO 0130-403 are analysed. The sample consists of 23 objects, none of which is detected at radio frequencies, with a median X-ray luminosity of ~4 × 1044 erg s-1 and redshifts ranging from ~0.1 to just over 3. Th…
Fitting optical source counts with an infrared-defined model: insights into galaxy evolution
Rowan-Robinson, M.; King, A. J.
In order to improve the fit to the optical counts, the recent multiwavelength source count model of Rowan-Robinson is improved in two ways. First, density evolution is incorporated to correspond to the mergers in hierarchical models of galaxy formation. Secondly, the evolution of dust opacity is taken into account. The luminosity and density evolu…
Crystalline water ice in OH32.8-0.3
Maldoni, M. M.; Robinson, G.; Wright, C. M. +2 more
The 2.2-200 µm spectrum of OH32.8-0.3 has been modelled. Mie theory and radiative transfer models of the 3-µm band of H2O ice are consistent with a strongly crystalline structural phase. This is also confirmed by the presence of a 44/62-µm band complex analogous to that of laboratory crystalline H2O ice anal…
A far-infrared view of the Lockman Hole from ISO 95-µm observations - I. A new data reduction method
Rodighiero, G.; Franceschini, A.; Lari, C. +2 more
We report results from a new analysis of a deep 95-µm imaging survey with the photopolarimeter ISOPHOT on-board the Infrared Space Observatory, over a 40 × 40 arcmin2 area within the Lockman Hole. To this end we exploit a newly developed parametric algorithm able to identify and clean spurious signals induced by cosmic rays impact…
Mid-infrared imaging of the dust shell around the post-asymptotic giant branch star HD 161796
Gledhill, T. M.; Yates, J. A.
We present mid-infrared (IR) images of HD 161796 (IRAS 17436+5003), taken with the OSCIR imager on the Gemini North Telescope, that resolve for the first time the thermal emission structure of the dust shell around this post-asymptotic giant branch (AGB) star. As well as a basic axisymmetric structure, the observations show deviations from axisymm…
High-resolution radio structure and optical kinematics of NGC 7027
Redman, M. P.; Bryce, M.; Thomasson, P. +2 more
We present the results of the highest-resolution 18-cm (L-band) radio continuum and optical kinematic studies to date of the young planetary nebula (PN), NGC 7027. We discuss the radio image of NGC 7027 made from combined data from the Multi-Element Radio-Linked Interferometer Network and the Very Large Array. This image is used to derive the dist…
QU Car: a very high luminosity nova-like binary with a carbon-enriched companion
Long, Knox S.; Drew, Janet E.; Hartley, Louise E. +1 more
QU Car is listed in cataclysmic variable star catalogues as a nova-like variable. This little-studied, yet bright interacting binary is re-appraised here in the light of new high-quality ultraviolet interstellar line data obtained with STIS on-board the Hubble Space Telescope. The detection of a component of interstellar absorption at a mean local…
On the nature of Collinder 121: insights from the low-mass pre-main sequence
Naylor, Tim; Jeffries, R. D.; Burningham, Ben +1 more
We present a VI photometric catalogue towards the open cluster Cr 121. XMM-Newton and ROSAT data are used to discover a low-mass pre-main sequence (PMS) along this sightline. de Zeeuw et al. have identified Cr 121 as a moving group, using Hipparcos data, at a distance of 592 pc; we reject the scenario that these low-mass PMS stars are associated w…
Chemical evolution of the M82 B fossil starburst
de Grijs, Richard; Gilmore, Gerry; Parmentier, Geneviève
M82 B is an old starburst site located in the eastern part of the M82 disc. We derive the distributions of age and metallicity of the star clusters located in this region of M82 by using theoretical evolutionary population synthesis models. Our analysis is based on the comparison of the BVIJ photometry obtained by de Grijs, O'Connel & Gallaghe…
On the nature of the ISO-selected sources in the ELAIS S2 region
Pozzi, F.; Calabrese, E.; Gruppioni, C. +7 more
We have studied the optical, near-infrared and radio properties of a complete sample of 43 sources detected at 15 µm in one of the deeper ELAIS repeatedly observed regions. The extragalactic objects in this sample have 15-µm flux densities in the range of 0.4-10 mJy, where the source counts start diverging from no evolution models. Abo…