Search Publications
Measuring and modelling the redshift evolution of clustering: the Hubble Deep Field North
Matarrese, S.; Fontana, A.; Cristiani, S. +4 more
The evolution of galaxy clustering from z=0 to z~=4.5 is analysed using the angular correlation function and the photometric redshift distribution of galaxies brighter than IAB<=28.5 in the Hubble Deep Field North. The reliability of the photometric redshift estimates is discussed on the basis of the available spectroscopic redshifts…
A comparative HST imaging study of the host galaxies of radio-quiet quasars, radio-loud quasars and radio galaxies - I
McLure, R. J.; Dunlop, J. S.; Hughes, D. H. +3 more
We present the first results from a major HST WFPC2 imaging study aimed at providing the first statistically meaningful comparison of the morphologies, luminosities, scalelengths and colours of the host galaxies of radio-quiet quasars, radio-loud quasars and radio galaxies. We describe the design of this study and present the images that have been…
The discovery of ERO counterparts to faint submillimetre galaxies
Kneib, J. -P.; Ivison, R. J.; Morrison, G. +5 more
We have used deep ground-based imaging in the near-infrared (near-IR) to search for counterparts to the luminous submillimetre (submm) sources in the catalogue of Smail et al. For the majority of the submm sources the near-IR imaging supports the counterparts originally selected from deep optical images. However, in two cases (10per cent of the sa…
A secondary clump of red giant stars: why and where
Girardi, Léo
Based on the results of detailed population synthesis models, Girardi et al. recently claimed that the clump of red giants in the colour-magnitude diagram (CMD) of composite stellar populations should present an extension to lower luminosities, which goes down to about 0.4mag below the main clump. This feature is made of stars just massive enough …
The domain of γ Doradus variables in the Hertzsprung-Russell diagram
Handler, G.
70 new γ Doradus candidates were identified from Hipparcos photometry, which represents more than a doubling of the presently known number. Selecting the objects with good evidence for multiperiodicity, it is found that these stars, together with bona fide members of the class, occupy a well-defined region in a colour-magnitude diagram. This domai…
The star formation history of the Hubble sequence: spatially resolved colour distributions of intermediate-redshift galaxies in the Hubble Deep Field
Fabian, A. C.; Glazebrook, K.; Abraham, R. G. +2 more
We analyse the spatially resolved colours of distant galaxies of known redshift in the Hubble Deep Field, using a new technique based on matching resolved four-band colour data to the predictions of evolutionary synthesis models. Given some simplifying assumptions, we demonstrate how our technique is capable of probing the evolutionary history of …
Velocity distribution of stars in the solar neighbourhood
Cottrell, P. L.; Hearnshaw, J. B.; Skuljan, J.
A two-dimensional velocity distribution in the UV plane has been obtained for stars in the solar neighbourhood, using Hipparcos astrometry for over 4000 `survey' stars with parallaxes greater than 10mas and radial velocities found in the Hipparcos Input Catalogue. In addition to the already known grouping characteristics (field stars plus young mo…
The properties of field elliptical galaxies at intermediate redshift - I. Empirical scaling laws
Treu, T.; Stiavelli, M.; Møller, P. +2 more
We present measurements of the Fundamental Plane (FP) parameters (the effective radius, the mean effective surface brightness, and the central velocity dispersion) of six field elliptical galaxies at intermediate redshift. The imaging is taken from the Medium Deep Survey of the Hubble Space Telescope, while the kinematical data are obtained from l…
Galactic bulges from Hubble Space Telescope NICMOS observations: ages and dust
Burkert, A.; Balcells, Marc; Peletier, Reynier F. +4 more
We present optical and near-infrared colour maps of the central regions of bulges of S0 and spiral galaxies obtained with WFPC2 and NICMOS on the Hubble Space Telescope (HST). By combined use of HST and ground-based data, the colour information spans a region from a few tens of pc to a few kpc. In almost all galaxies, the colour profiles in the ce…
Dynamical models of NGC 3115
Bacon, Roland; Emsellem, Eric; Dejonghe, Herwig
We present new dynamical models of the S0 galaxy N3115, making use of the available published photometry and kinematics as well as two-dimensional TIGER spectrography. The models are based on a detailed model of the luminosity distribution built using an MGE fit on HST/WFPC2 and ground-based photometric data. We first examined the kinematics in th…