Search Publications
Circumnuclear regions in barred spiral galaxies - II. Relations to host galaxies
Knapen, J. H.; Pérez-Ramírez, D.; Laine, S.
We present optical broad- and narrow-band imaging of a sample of a dozen barred galaxies. These images are analysed in conjunction with our previously published near-infrared imaging of their central regions and with literature values for, e.g. bar strengths and the total star formation activity of the galaxies. We present B, I and Hα images, and …
A Hubble Space Telescope lensing survey of X-ray-luminous galaxy clusters - II. A search for gravitationally lensed EROs *
Kneib, J. -P.; Ivison, R. J.; Smith, Graham P. +7 more
We present the results of a survey for extremely red objects (EROs) undertaken in the fields of 10 massive galaxy cluster lenses at , combining sensitive, high-resolution Hubble Space Telescope imaging with deep, half-arcsecond K -band imaging from UKIRT. We detect 60 EROs with , of which 26 have in a total image-plane survey area of 49arcmin…
K dwarfs and the chemical evolution of the solar cylinder
Chiappini, Cristina; Matteucci, Francesca; Flynn, Chris +1 more
K dwarfs have lifetimes older than the present age of the Galactic disc, and are thus ideal stars for investigating the chemical evolution of the disc. We have developed several photometric metallicity indicators for K dwarfs, based on a sample of accurate spectroscopic metallicities for 34 disc and halo G and K dwarfs. The photometric metalliciti…
Mass segregation in young compact star clusters in the Large Magellanic Cloud - I. Data and luminosity functions
de Grijs, R.; Gilmore, G. F.; Johnson, R. A. +1 more
We have undertaken a detailed analysis of HST/WFPC2 and STIS imaging observations, and of supplementary wide-field ground-based observations obtained with the ESO New Technology Telescope (NTT) of two young (~10-25Myr) compact star clusters in the LMC, NGC 1805 and 1818. The ultimate goal of our work is to improve our understanding of the degree o…
Echoes in X-ray binaries
Horne, Keith; O'Brien, K.; Chen, W. +3 more
We present a method of analysing the correlated X-ray and optical/UV variability in X-ray binaries, using the observed time delays between the X-ray driving light curves and their reprocessed optical echoes. This allows us to determine the distribution of reprocessing sites within the binary. We model the time-delay transfer functions by simulatin…
Mass segregation in young compact clusters in the Large Magellanic Cloud - III. Implications for the initial mass function
Santiago, B. X.; Mackey, A. D.; de Grijs, R. +4 more
The distribution of core radii of rich clusters in the Large Magellanic Cloud (LMC) systematically increases in both upper limit and spread with increasing cluster age. Cluster-to-cluster variations in the stellar initial mass function (IMF) have been suggested as an explanation. We discuss the implications of the observed degree of mass segregati…
The SCUBA 8-mJy survey - II. Multiwavelength analysis of bright submillimetre sources
Ivison, R. J.; Dunlop, J. S.; Serjeant, S. +13 more
We present the results of a multiwavelength study of the 19 most significant submillimetre (submm) sources detected in the SCUBA 8-mJy survey. As described in Scott et al. , this survey covers ~=260arcmin2 using the submillimetre camera SCUBA, to a limiting source detection limit S 850µm ~=8mJy. One advantage of this re…
High-resolution X-ray imaging and spectroscopy of the core of NGC 4945 with XMM-Newton and Chandra
Schurch, N. J.; Warwick, R. S.; Roberts, T. P.
We utilize the complementary capabilities of XMM-Newton and Chandra to conduct a detailed imaging and spectral study of the nearby galaxy NGC 4945 focusing on its nucleus and immediate surroundings (within ~ kpc of the nucleus). A complex morphology is revealed including a predominantly hard, but partially resolved, nuclear source plus a spectrall…
An Hα survey of the rich cluster A 1689
Smail, Ian; Glazebrook, Karl; Balogh, Michael L. +2 more
We present results of an Hα survey in the rich cluster A 1689 at z= 0.18, using the LDSS++ spectrograph on the Anglo-Australian Telescope (AAT). We obtained spectra covering redshifted Hα at z= 0.16-0.22, for 522 galaxies brighter than I= 22.5, covering a field of 8.7 × 8.7 arcmin2 (~1.1 × 1.1 h-1 Mpc at z= 0.18). We securely…
The ultraviolet line spectrum of the soft X-ray transient XTE J1118+480: a CNO-processed core exposed
King, A. R.; Haswell, C. A.; Hynes, R. I. +1 more
We compare ultraviolet (UV) spectra of the recent soft X-ray transients XTE J1118+480 and XTE J1859+226. The emission line strengths in XTE J1118+480 strongly suggest that the accreting material has been CNO processed. We show that this system must have come into contact with a secondary star of about 1.5Msolar, and an orbital period ~1…