Search Publications
How extreme are the Wolf-Rayet clusters in NGC3125?*
Crowther, P. A.; Hadfield, L. J.
We reinvestigate the massive stellar content of the irregular dwarf galaxy NGC3125 (Tol 3) using Very Large Telescope (VLT)/FORS1 imaging and spectroscopy, plus archival VLT/ISAAC, Hubble Space Telescope (HST)/FOC and HST/STIS data sets. FORS1 narrow-band imaging confirms that the NGC3125-A and -B knots represent the primary sites of Wolf-Rayet (W…
XMM-Newton observations of the black hole X-ray transient XTE J1650-500 in quiescence
Homan, Jeroen; Miller, Jon M.; Belloni, Tomaso +4 more
We report the result of an XMM-Newton observation of the black hole X-ray transient XTE J1650-500 in quiescence. The source was not detected, and we set upper limits on the 0.5-10 keV luminosity of 0.9-1.0 × 1031 ergs-1 (for a newly derived distance of 2.6 kpc). These limits are in line with the quiescent luminosities of blac…
Integral field spectroscopy of Hα emission in cooling flow cluster cores: disturbing the molecular gas reservoir
Swinbank, A. M.; Edge, A. C.; Wilman, R. J.
We present optical integral field spectroscopy of the Hα-luminous (>1042ergs-1) central cluster galaxies in the cores of the cooling flow clusters A1664, A1835, A2204 and Zw8193. From the [NII]+Hα complex in these moderate resolution (70-150kms-1) spectra we derive 2D views of the distribution and kinematics of …
New members in the Upper Scorpius association from the UKIRT Infrared Deep Sky Survey Early Data Release†
Hambly, N. C.; Jameson, R. F.; Lodieu, N.
We present the results of a 9.3-deg2 infrared (ZYJHK) survey in the Upper Scorpius association extracted from the UKIRT Infrared Deep Sky Survey (UKIDSS) Galactic Cluster Survey Early Data Release. We have selected a total of 112 candidates from the (Z-J, Z) colour-magnitude diagram over the Z= 12.5-20.5 magnitude range, corresponding t…
The globular cluster kinematics and galaxy dark matter content of NGC 4649 (M60)
Forbes, Duncan A.; Beasley, Michael A.; Zepf, Stephen E. +7 more
From observations with the GMOS multislit spectrograph on the Gemini North telescope, we have obtained spectra for 39 globular cluster (GC) candidates in the Virgo giant elliptical galaxy NGC 4649 (M60), of which 38 are confirmed GCs. The clusters extend out to a radius of 260 arcsec (3.5 effective radii). We find no rotation of the GC system, wit…
The BH mass of nearby QSOs: a comparison of the bulge luminosity and virial methods
Falomo, R.; Uslenghi, M.; Treves, A. +1 more
We report on the analysis of the photometric and spectroscopic properties of a sample of 29 low-redshift (z < 0.6) QSOs for which both Hubble Space Telescope (HST) WFPC2 images and ultraviolet HST FOS spectra are available. For each object we measure the R-band absolute magnitude of the host galaxy, the CIV(1550Å) linewidth and the 1350Å contin…
XMM-Newton observations of bright ROSAT selected active galactic nuclei with low intrinsic absorption
Pietsch, W.; Boller, Th.; Brinkmann, W. +4 more
We present a sample of 21 ROSAT bright active galactic nuclei (AGNs), representing a range of spectral classes, and selected for follow-up snapshot observations with XMM-Newton. The typical exposure was between 5 and 10ks. The objects were primarily selected on the bases of X-ray brightness and not on hardness ratio; thus the sample cannot be stri…
Formation and evolution of late-type dwarf galaxies - I. NGC1705 and NGC1569
Matteucci, Francesca; Tosi, Monica; Romano, Donatella
We present one-zone chemical evolution models for two dwarf starburst galaxies, NGC1705 and NGC1569. Though especially designed for the inner ~1 kpc region, where numerous HII regions and most of the stars are observed, the models also account for the presence of extended gaseous and dark matter haloes, and properly compute the binding energy of t…
An ultradeep submillimetre map: beneath the SCUBA confusion limit with lensing and robust source extraction
Smail, I.; Kneib, J. -P.; Ivison, R. J. +7 more
Extracting sources with low signal-to-noise ratio (S/N) from maps with structured background is a non-trivial task which has become important in studying the faint end of the submillimetre (submm) number counts. In this paper, we study the source extraction from submm jiggle-maps from the Submillimetre Common-User Bolometer Array (SCUBA) using the…
An imaging study of the globular cluster systems of NGC 1407 and 1400
Forbes, Duncan A.; Brodie, Jean P.; Strader, Jay +3 more
We present wide-field Keck telescope imaging of the globular cluster (GC) systems around NGC 1407 and 1400 in the Eridanus galaxy cloud. This is complemented by Hubble Space Telescope (HST) images from the Advanced Camera for Surveys of NGC 1407 and Wide Field and Planetary Camera 2 images of NGC 1400. We clearly detect bimodality in the GC colour…