Search Publications
Some statistical aspects of estimating the local red clump absolute magnitude
Koen, Chris; Lombard, Fred
Various statistical issues regarding estimation of the mean absolute magnitude of the red clump stars, using Hipparcos parallaxes, are discussed. The problem is put in the broader context of estimation of the functional dependence of the absolute magnitude on colour of local giant stars, as derived from Hipparcos observations. The methods used inc…
On the origin of the X-ray emission from a narrow-line radio quasar at z > 1
Barcons, X.; Carballo, R.; Warwick, R. S. +5 more
We present new XMM-Newton X-ray observations of the z= 1.246 narrow-line radio quasar RX J1011.2+5545 serendipitously discovered by ROSAT. The flat X-ray spectrum previously measured by ROSAT and ASCA is shown to be the result of a steep Γ~ 1.8 power-law spectrum seen through a moderate intrinsic absorbing column (NH~ 4 × 1021
On the importance of searching for oscillations of the Jovian inner radiation belt with a quasi-period of 40 minutes
Lou, Yu-Qing; Zheng, Chen
Experiments aboard the Ulysses spacecraft discovered quasi-periodic bursts of relativistic electrons and of radio emissions with ~40-min period (QP-40) from the south polar direction of Jupiter in 1992 February. Such polar QP-40 burst activities were found to correlate well with arrivals of high-speed solar winds at Jupiter. We advance the physica…
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…
Measuring the black hole masses of high-redshift quasars
McLure, R. J.; Jarvis, M. J.
A new technique is presented for determining the black hole masses of high-redshift quasars from optical spectroscopy. The new method utilizes the full-width at half-maximum (FWHM) of the low-ionization MgII emission line and the correlation between the broad-line region (BLR) radius and the continuum luminosity at 3000 Å. Using archival ultraviol…
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…
Deep radio imaging of the SCUBA 8-mJy survey fields: submillimetre source identifications and redshift distribution
Ivison, R. J.; Smail, Ian; Dunlop, J. S. +12 more
The SCUBA 8-mJy survey is the largest submillimetre (submm) extragalactic mapping survey undertaken to date, covering 260 arcmin2 to a 4 σ detection limit of ~=8 mJy at 850 µm, centred on the Lockman Hole and ELAIS N2 regions. Here, we present the results of new 1.4-GHz imaging of these fields, of the depth and resolution necessar…
A long hard look at MCG-6-30-15 with XMM-Newton
Young, A. J.; Nandra, K.; Iwasawa, K. +6 more
We present the first results from a 325-ks observation of the Seyfert 1 galaxy MCG-6-30-15 with XMM-Newton and BeppoSAX. The strong, broad, skewed iron line is clearly detected and is well characterized by a steep emissivity profile within 6rg (i.e. 6GM/c2) and a flatter profile beyond. The inner radius of the emission appear…