Search Publications
The SAURON project - III. Integral-field absorption-line kinematics of 48 elliptical and lenticular galaxies
Krajnović, Davor; Emsellem, Eric; Miller, Bryan W. +9 more
We present the stellar kinematics of 48 representative elliptical and lenticular galaxies obtained with our custom-built integral-field spectrograph SAURON operating on the William Herschel Telescope. The data were homogeneously processed through a dedicated reduction and analysis pipeline. All resulting SAURON data cubes were spatially binned to …
The star formation rate of the Universe at z~ 6 from the Hubble Ultra-Deep Field
Bunker, Andrew J.; McMahon, Richard G.; Ellis, Richard S. +1 more
We determine the abundance of i'-band dropouts in the recently released HST/ACS Hubble Ultra-Deep Field (UDF). Because the majority of these sources are likely to be z~ 6 galaxies whose flux decrement between the F775W i'-band and F850LP z'-band arises from Lyman-α absorption, the number of detected candidates provides a valuable upper limit to th…
Comparing the properties of local globular cluster systems: implications for the formation of the Galactic halo
Mackey, A. D.; Gilmore, G. F.
We investigate the hypothesis that some fraction of the globular clusters presently observed in the Galactic halo formed in external dwarf galaxies. This is done by means of a detailed comparison between the `old halo', `young halo' and `bulge/disc' subsystems defined by Zinn and the globular clusters in the Large Magellanic Cloud, Small Magellani…
High-resolution imaging of the HeII λ4686 emission line nebula associated with the ultraluminous X-ray source in Holmberg II
Zezas, A.; Kaaret, P.; Ward, M. J.
We present Hubble Space Telescope images of the HeIII region surrounding the bright X-ray source in the dwarf irregular galaxy Holmberg II. Using Chandra, we find a position for the X-ray source of (J2000) with an uncertainty of 0.6 arcsec. We identify a bright, point-like optical counterpart centred in the nebula with the X-ray source. The optica…
Analysing observed star cluster SEDs with evolutionary synthesis models: systematic uncertainties
de Grijs, R.; Anders, P.; Fritze-v. Alvensleben, U. +1 more
We discuss the systematic uncertainties inherent to analyses of observed (broad-band) spectral energy distributions (SEDs) of star clusters with evolutionary synthesis models. We investigate the effects caused by restricting oneself to a limited number of available passbands, choices of various passband combinations, finite observational errors, n…
The host galaxies of luminous quasars
Baum, Stefi A.; O'Dea, Christopher P.; Dunlop, James S. +5 more
We present the results of a deep Hubble Space Telescope (HST)/Wide Field and Planetary Camera 2 imaging study of 17 quasars at z~= 0.4, designed to determine the properties of their host galaxies. The sample consists of quasars with absolute magnitudes in the range -24 >=MV>=- 28, allowing us to investigate host galaxy properties …
A sample of radio galaxies spanning three decades in radio luminosity - I. The host galaxy properties and black hole masses
Willott, Chris J.; Rawlings, Steve; Jarvis, Matt J. +5 more
The results of analysis of HST I-band imaging of a sample of 41 radio galaxies spanning three orders of magnitude in radio luminosity at redshift z~= 0.5 are presented. These results represent the first stage in a coordinated programme to study the connection between radio luminosity and host galaxy properties, black hole masses and cluster enviro…
A panoramic Hα imaging survey of the z= 0.4 cluster Cl0024.0+1652 with Subaru
Smail, Ian; Kodama, Tadayuki; Nakata, Fumiaki +2 more
We employ panoramic, multicolour (BRz') and narrow-band Hα imaging of the cluster Cl0024.0+1652 (z= 0.39) from Subaru covering a ~30-arcmin field, to determine cluster membership and star formation rates for a large sample of galaxies across a wide field in the cluster, ~10 Mpc. We use photometric redshifts to identify cluster members, and statist…
A transition in the accretion properties of radio-loud active nuclei
Marchesini, Danilo; Ferrarese, Laura; Celotti, Annalisa
We present evidence for the presence of a transition in the accretion properties of radio-loud sources. For a sample of radio galaxies and radio-loud quasars, selected based on their extended radio properties, the accretion rate is estimated from the black hole mass and nuclear luminosity. The inferred distribution is bimodal, with a paucity of so…
Discovery of the galaxy counterpart of HDF 850.1, the brightest submillimetre source in the Hubble Deep Field
Muxlow, T. W. B.; Smail, I.; Smith, G. P. +14 more
Despite extensive observational efforts, a convincing optical/infrared identification of the brightest submm source in the Hubble Deep Field, HDF 850.1, has remained elusive after almost four years. This failure is all the more notable given the availability of supporting multifrequency data of unparalleled depth, and subarcsec positional accuracy…