Search Publications
An infrared study of the double nucleus in NGC3256
Hoyer, S.; Ward, M.; Lira, P. +1 more
We present new resolved near- and mid-infrared (mid-IR) imaging and N-band spectroscopy of the two nuclei in the merger system NGC3256, the most IR luminous galaxy in the nearby Universe. The results from the spectral energy distribution fit to the data are consistent with previous estimates of the amount of obscuration towards the nuclei and the …
Probing the slope of cluster mass profile with gravitational Einstein rings: application to Abell 1689
Jullo, E.; Fort, B.; Richard, J. +5 more
The strong lensing modelling of gravitational 'rings' formed around massive galaxies is sensitive to the amplitude of the external shear and convergence produced by nearby mass condensations. In current wide-field surveys, it is now possible to find out a large number of rings, typically 10 gravitational rings per square degree. We propose here, t…
M dwarfs at large heliocentric distances
Lehnert, Matthew D.; Stanway, Elizabeth R.; Bremer, Malcolm N. +1 more
We present an analysis of the faint M star population seen as foreground contaminants in deep extragalactic surveys. We use space-based data to separate such stars from high-redshift galaxies in a publicly available data set, and consider the photometric properties of the resulting sample in the optical and infrared. The inferred distances place t…
Absolute dimensions and apsidal motion of the eccentric binary PT Velorum
Demircan, O.; Bakış, V.; Eker, Z. +1 more
High-resolution (λ/dλ ~ 41000) echelle spectra of the eccentric binary system PT Vel were analysed. Precise spectroscopic orbital elements of the system were obtained by means of cross-correlation technique. According to the solution of radial velocities with Hipparcos and All Sky Automated Survey-3 (ASAS-3) light curves, PT Vel consists of two ma…
3C40 in Abell194: can tail radio galaxies exist in a quiescent cluster?
Hardcastle, M. J.; Sakelliou, Irini; Jetha, N. N.
The nearby cluster Abell194 hosts two luminous, distorted radio galaxies. Both reside within the cluster's core region, being separated in projection by only 100 kpc. It is often suggested that tailed radio galaxies such as these reside in clusters that are under formation and are accreting new material from their outskirts. In this paper, we stud…
Spectroscopic and photometric observations of the selected Algol-type binaries - II. V2080 Cygni and V2365 Ophiuchi
Frasca, A.; Çakırlı, Ö.; Sipahi, E. +9 more
This paper is the second in the planned series of investigations. We present new radial velocities and photometric observations of V2080 Cyg and V2365 Oph. New UBV photometric data and radial velocities were analysed for the systems' parameters. While V2080 Cyg consists of two nearly equal F-type main-sequence stars, V2365 Oph has two different co…
The iron abundance of the Magellanic Bridge
Dufton, P. L.; Thompson, H. M. A.; Ryans, R. S. I. +1 more
High-resolution Hubble Space Telescope ultraviolet spectra for five B-type stars in the Magellanic Bridge and in the Large (LMC) and Small (SMC) Magellanic Clouds have been analysed to estimate their iron abundances. Those for the Clouds are lower than estimates obtained from late-type stars or the optical lines in B-type stars by approximately 0.…
Physical parameters for Orion KL from modelling its ISO high-resolution far-IR CO line spectrum
White, G. J.; Barlow, M. J.; Cernicharo, J. +5 more
As part of the first high-resolution far-infrared (far-IR) spectral survey of the Orion Kleinmann-Low (KL) region, we observed 20 CO emission lines with Jup = 16 to 39 (upper levels from ~752 to 4294 K above the ground state). Observations were taken using the Long Wavelength Spectrometer on board the Infrared Space Observatory (ISO), i…
Correlated spectral variability in brown dwarfs
Bailer-Jones, C. A. L.
Models of brown dwarf atmospheres suggest they exhibit complex physical behaviour. Observations have shown that they are indeed dynamic, displaying small photometric variations over time-scales of hours. Here, I report results of infrared (0.95-1.64 µm) spectrophotometric monitoring of four field L and T dwarfs spanning time-scales of 0.1-5.…
Near ultraviolet-infrared colours of red-sequence galaxies in local clusters
Hudson, Michael J.; Lucey, John R.; Smith, Russell J. +2 more
We present GALEX near-ultraviolet (NUV) and Two-Micron All-Sky Survey J-band photometry for red-sequence galaxies in local clusters. We define quiescent samples according to a strict emission threshold, removing galaxies with very recent star formation. We analyse the NUV-J colour-magnitude relation (CMR) and find that the intrinsic scatter is an …