The kinematic Sunyaev Zeldovich effect and transverse cluster velocities

The polarization of the CMBR scattered by galaxy clusters in the kinematic Sunyaev Zeldovich effect depends on the transverse velocity of the cluster. This polarizing effect is proportional to the transverse velocity squared, and so weaker that the change in intensity due to the radial motion in the kinematic effect. The value given by Sunyaev and Zeldovich, and which is frequently cited, underestimates the polarizing effect by a factor of ten. We show furthermore that the polarization has a strong frequency dependence. This means that the polarization should be detectable with the new generation of CMBR probes, at least for some clusters. Thus this effect offers, almost uniquely, a method of obtaining the vectorial velocity of clusters.Comment: Submitted to MNRAS letter. 5 pages using mnras file style. email: [email protected]

From individualism to co-construction and back again:Rethinking research methodology for children with profound and multiple learning disabilities

Children with profound and multiple learning disabilities (PMLD) are said to experience severe congenital impairments to consciousness and cognition stemming from neurological damage. Such children are understood as operating at the pre-verbal stages of development, and research in the field typically draws conceptual resources from psychology to devise educational interventions and assessment tools. Criticism has been levelled at studies that treat children with PMLD as objects of research rather than subjects to be consulted. Proponents of the latter view have attempted to redress the situation by exploring how personal experiences can be gleaned through adapted qualitative methods. Debate about methodology in the PMLD field tends to coalesce around these individualist polemics: either children with PMLD are positioned as incompetent and lacking voice; or researchers are positioned as lacking the appropriate tools to gain access to such voice. This paper offers an alternative position to the individualism of post-positivist/constructivist approaches, identifying the need for a critical and participatory approach that sees knowledge about children with PMLD as situated and co-constructed through regular and longitudinal interaction between the researcher, children with PMLD, and significant others. Context to this argument is provided by exploring the application of this approach to an inclusive education research project for a child with PMLD

The use of light polarization for weak-lensing inversions

The measurement of the integrated optical polarization of weakly gravitationally lensed galaxies can provide considerable constraints on lens models. The method outlined depends on fact that the orientation of the direction of optical polarization is not affected by weak gravitational lensing. The angle between the semi-major axis of the imaged galaxy and the direction of integrated optical polarization thus informs one of the distortion produced by the gravitational lensing. Although the method depends on the polarimetric measurement of faint galaxies, large telescopes and improved techniques should make such measurements possible in the near future.Comment: 13 pages, 11 figures, uses mnras style file. Accepted for publication in MNRA

Indexed keyed connection Patent

Standard coupling design for mass productio

Optimal Galaxy Distance Estimators

The statistical properties of galaxy distance estimators are studied and a rigorous framework is developed for identifying and removing the effects of Malmquist bias due to obsevational selection. The prescription of Schechter (1980) for defining unbiased distance estimators is extended to more general -- and more realistic -- cases. The derivation of `optimal' unbiased distance estimators of minimum dispersion, by utilising information from additional -- suitably correlated -- observables, is discussed and the results applied to a calibrating sample from the Fornax cluster, as used in the Mathewson spiral galaxy redshift survey. The optimal distance estimator derived from I-band magnitude, diameter and 21cm line width has an intrinsic scatter which is 25 \% smaller than that of the Tully-Fisher relation quoted for this calibrating sample. (Figures are available on request).Comment: Plain Latex, 19 pages, Sussex-AST-93/9-

Mission oriented study of advanced nuclear system parameters, phase IV, volume I Final report, May 1965 - Dec. 1966

Guidelines and assumptions for manned Mars stopover mission planning analyses - nuclear system parameter