Search Publications
The radio galaxy 3C 356 and clues to the trigger mechanisms for powerful radio sources
Simpson, Chris; Rawlings, Steve
We present deep near-infrared images, taken with the Subaru Telescope, of the region around the z=1.08 radio source 3C 356 which show it to be associated with a poor cluster of galaxies. We discuss evidence that this cluster comprises two subclusters traced by the two galaxies previously proposed as identifications for 3C 356, which both seem to h…
Restrictions to the galaxy evolutionary models from the Hawaiian Deep Fields SSA13 and SSA22
Aguerri, J. A. L.; Trujillo, I.
Quantitative structural analysis of the galaxies present in the Hawaiian Deep Fields SSA13 and SSA22 is reported. The structural parameters of the galaxies have been obtained automatically by fitting a two-component model (Sérsic r1/n bulge and exponential disc) to the surface brightness of the galaxies. The galaxies were classified on …
Old elliptical galaxies at z ~= 1.5 and the Kormendy relation
Stern, D.; McLure, R. J.; Dunlop, J. S. +8 more
Deep spectroscopy of the two Leiden-Berkeley Deep Survey mJy radio galaxies LBDS 53W069 and 53W091 has previously shown them to have old (>~3 Gyr) stellar populations at z~= 1.5. Here we present the results of Hubble Space Telescope (HST) observations with the Wide Field and Planetary Camera 2 (WFPC2) in F814W and with the Near-Infrared Camera …
Enhancement of the helium resonance lines in the solar atmosphere by suprathermal electron excitation - I. Non-thermal transport of helium ions
Jordan, C.; Smith, G. R.
Models of the solar transition region made from lines other than those of helium cannot account for the strength of the helium lines. However, the collisional excitation rates of the helium resonance lines are unusually sensitive to the energy of the exciting electrons. Non-thermal motions in the transition region could drive slowly ionizing heliu…
Near- and mid-infrared colours of star-forming galaxies in European Large Area ISO Survey fields
Serjeant, S.; Morel, T.; Gruppioni, C. +6 more
We present J- and K-band near-infrared (near-IR) photometry of a sample of mid-infrared (mid-IR) sources detected by the Infrared Space Observatory (ISO) as part of the European Large Area ISO Survey (ELAIS) and study their classification and star-forming properties. We have used the Preliminary ELAIS Catalogue for the 6.7-µm (LW2) and 15-&m…
XMM-Newton observations of the asynchronous polar BY Cam
Cropper, Mark; Ramsay, Gavin
We report observations of the asynchronous polar BY Cam made using XMM-Newton. We find evidence for two accretion regions which have significantly different spectra. In both regions we find evidence for hard X-ray emission from the post-shock flow while we observe a distinct soft X-ray blackbody component in only one. We detect two emission lines …
On the pulsation parallax of the variable star RR Lyr
Marconi, M.; Bono, G.; Caputo, F. +2 more
We show that a straightforward application of the predicted relation connecting the absolute K magnitude of fundamental RR Lyrae variables to their period and metal content, together with current evolutionary predictions on the mass and luminosity of Horizontal Branch stars, supply a distance estimate to the prototype star RR Lyr in close agreemen…
An irradiated accretion disc in the narrow-line Seyfert 1 RE J1034+396?
Soria, R.; Puchnarewicz, E. M.
We model the optical to X-ray continuum spectrum of the narrow-line Seyfert 1 galaxy RE J1034+396. We show that the flat optical spectrum is consistent with emission from an irradiated accretion disc. The X-ray emission can be modelled with a disc blackbody and a Comptonized component. The temperature at the inner edge of the disc Tin=(…
The host galaxies of Type Ia supernovae at z= 0.6
Farrah, D.; Rowan-Robinson, M.; Mattila, S. +2 more
We examine the host galaxies of high-redshift Type Ia supernovae (SNe Ia) using archival I- and R-band data from the Hubble Space Telescope. The SNe Ia host galaxies show a wide variety of morphologies, including undisturbed ellipticals, spirals and disturbed systems. SNe Ia are also found over a wide range of projected distances from the host gal…
The massive double-lined O-type binary HD 165052
Barbá, R. H.; Morrell, N. I.; Arias, J. I. +3 more
We present a new optical spectroscopic study of the O-type binary HD 165052 based on high- and intermediate-resolution CCD observations. We re-investigated the spectral classification of the binary components, obtaining spectral types of O6.5V and O7.5V for the primary and secondary, respectively, finding that both stars display weak CIIIλ5696 emi…