Constraining the parameters of binary systems through time-dependent light deflection

A theory is derived relating the configuration of the cores of active galaxies, specifically candidates for presumed super-massive black hole binaries (SMBHBs), to time-dependent changes in images of those galaxies. Three deflection quantities, resulting from the monopole term, mass quadrupole term, and spin dipole term of the core, are examined. The resulting observational technique is applied to the galaxy 3C66B. This technique is found to under idealized circumstances surpass the technique proposed by Jenet et al. in accuracy for constraining the mass of SMBHB candidates, but is exceeded in accuracy and precision by Jenet's technique under currently-understood likely conditions. The technique can also under favorable circumstances produce results measurable by currently-available astronomical interferometry such as very-long baseline-interferometry (VLBI).Comment: 15 pages, 2 figures, accepted in General Relativity & Gravitatio

Adaptation reveals sensory and decision components in the visual estimation of locomotion speed

Locomotion speed provides important social information about an individual’s fitness, mood and intent. Visual estimation of locomotion speed is a complex task for the visual system because viewing distance must be taken into account, and the estimate has to be calibrated by recent experience of typical speeds. Little is known about how locomotion speed judgements are made. Previous research indicates that the human visual system possesses neurons that respond specifically to moving human forms. This research used point-light walker (PLW) displays that are known to activate these cells, in order to investigate the process mediating locomotion speed judgements. The results of three adaptation experiments show that these judgements involve both a low-level sensory component and a high-level decision component. A simple theoretical scheme is proposed, in which neurons sensitive to image flicker rate (temporal frequency) provide a sensory speed code, and a benchmark ‘norm’ value of the speed code, based on prevailing locomotion speeds, is used to make decisions about objective speed. The output of a simple computational model of the scheme successfully captured variations in locomotion speed in the stimuli used in the experiments. The theory offers a biologically-motivated account of how locomotion speed can be visually estimated

Estimating Sea Surface Temperature from Infrared Satellite and In Situ Temperature Data.

Abstract not availableJRC.(SAI)-Space Application Institut

Interaction at mm and optical frequencies. Pt. 1 Current problems in radiative transfer simulations. Final report

An extensive literature survey of recent developments in the field of radiative transfer has been done. Within the scope of plane-parallel solutions of the RTE several solution methods have been presented: E.g. spherical harmonics, discrete ordinates, adding, doubling, matrix-operator, finite difference, and Gauss Seidel iteration. Solutions of the vector RTE permitting to take into account polarization and the subject of multidimensional geometry have been examined. General information and some models commonly used for solving the spherical RTE are presented. The subjects of RTM at millimetre wavelengths and the state of considering non-LTE effects has been reviewed. Models for the purpose of spectral integration have been discussed: GOMETRAN, LOWTRAN, MODTRAN, FASCOD-3, GENLN-2, and RADTRAN. Processes in the atmosphere influencing radiative transfer have been discussed: Monochromatic molecular absorption/emission properties (line parameters, line-mixing, and Dicke effect), broadband features (if required), scattering, properties of clouds and aerosols, and the lower boundary condition. Within a review of campaigns the validation problem has been discussed. (orig./KW)SIGLEAvailable from TIB Hannover: RR 1857(17) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekEuropean Space Agency (ESA), 75 - Paris (France)DEGerman

Interaction at mm and optical frequencies. Pt. 2 Specific atmospheric absorption and emission features: Investigation and modelling. Final report

This study deals with: Numerical analysis of the accuracy of recent models for atmospheric molecular absorption, in particular, studies of line mixing, line narowing (Dicke effect) and line shift effects; Establishment of a radiative transfet code for the computation of non-LTE outgoing radiation in the infrared spectrum; Analysis of up-to-date accuracy of initial spectroscopic information and its influence on outgoing radiation calculations in different spectral domains; Numerical investigations of the errors due to calculations of transmittance and outgoing radiation by k-distribution method. The investigations performed permit a more accurate estimate of up-to-date methods and algorithms for the calculation of atmospheric radiative transfer and to supply enhanced radiative transfer codes. (orig./KW)SIGLEAvailable from TIB Hannover: RR 1857(18) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekEuropean Space Agency (ESA), 75 - Paris (France)DEGerman