Search Publications
The SAURON project - II. Sample and early results
Emsellem, Eric; Miller, Bryan W.; Carollo, C. M. +9 more
Early results are reported from the SAURON survey of the kinematics and stellar populations of a representative sample of nearby E, S0 and Sa galaxies. The survey is aimed at determining the intrinsic shape of the galaxies, their orbital structure, the mass-to-light ratio as a function of radius, the age and metallicity of the stellar populations,…
Numerical methods of star formation history measurement and applications to seven dwarf spheroidals
Dolphin, A. E.
A comprehensive study of the measurement of star formation histories from colour-magnitude diagrams (CMDs) is presented, with an emphasis on a variety of subtle issues involved in the generation of model CMDs and maximum likelihood solution. Among these are the need for a complete sampling of the synthetic CMD, the use of proper statistics for dea…
Efficient multi-Gaussian expansion of galaxies
Cappellari, Michele
We describe a simple, efficient, robust and fully automatic algorithm for the determination of a multi-Gaussian expansion (MGE) fit to galaxy images, to be used as a parametrization for the galaxy stellar surface brightness. In most cases the least-squares solution found by this method essentially corresponds to the minimax, constant relative erro…
The nature of faint submillimetre-selected galaxies
Kneib, J. -P.; Ivison, R. J.; Smail, Ian +1 more
We present the source catalogue for the SCUBA Lens Survey. We summarize the results of extensive multiwavelength observations of the 15 submillimetre-selected galaxies in the catalogue, from X-rays to radio. We discuss the main observational characteristics of faint submillimetre galaxies as a population, and consider their interpretation within t…
Measuring the redshift evolution of clustering: the Hubble Deep Field South
Colombi, S.; Matarrese, S.; Fontana, A. +6 more
We present an analysis of the evolution of galaxy clustering in the redshift interval 0<=z<=4.5 in the Hubble Deep Field South (HDF-South). The HST optical data are combined with infrared ISAAC/VLT observations, and photometric redshifts are used for all the galaxies brighter than IAB<=27.5. The clustering signal is obtained in…
A SAURON study of M32: measuring the intrinsic flattening and the central black hole mass
Copin, Y.; van der Marel, R. P.; de Zeeuw, P. T. +6 more
We present dynamical models of the nearby compact elliptical galaxy M32, using high-quality kinematic measurements, obtained with the integral-field spectrograph SAURON mounted on the William Herschel Telescope on La Palma. We also include STIS data obtained previously by Joseph et al. We find a best-fitting black hole mass of M•= (2.5 …
The internal structure of the lens PG1115+080: breaking degeneracies in the value of the Hubble constant
Treu, T.; Koopmans, L. V. E.
We combine lensing, stellar kinematic and mass-to-light ratio constraints to build a two-component (luminous plus dark) mass model of the early-type lens galaxy in PG1115+080. We find a total mass density profile steeper than r-2, effectively ρ~r-γ' with γ'= 2.35 +/- 0.1 +/- 0.05 (random + systematic). The stellar mass fracti…
Galaxy cores as relics of black hole mergers
van den Bosch, Frank C.; Rest, Armin; Merritt, David +1 more
We investigate the hypothesis that the cores of elliptical galaxies and bulges are created from the binding energy liberated by the coalescence of supermassive binary black holes during galaxy mergers. Assuming that the central density profiles of galaxies were initially steep power laws, ρ ~r -2 , we define the `mass deficit' as the ma…
Spatially resolved X-ray spectroscopy of the core of the Centaurus cluster
Fabian, A. C.; Sanders, J. S.
We present Chandra data from a 31.7-ks observation of the Centaurus cluster, using the ACIS-S detector. Images of the X-ray emission show a plume-like feature at the centre of the cluster, of extent 60arcsec (20kpc in projection). The feature has the same metallicity as gas at a similar radius, but is cooler. Using adaptive binning, we generate te…
The physical properties of the Lyα forest at z > 1.5
Cristiani, S.; Giallongo, E.; Carswell, R. F. +2 more
Combining a new, increased data set of eight quasi-stellar objects (QSOs) covering the Lyα forest at redshifts 1.5 > z < 3.6 from VLT/UVES observations with previously published results, we have investigated the properties of the Lyα forest at 1.5 < z <4. With the six QSOs covering the Lyα forest at 1.5 < z < 2.5, we have extende…