The Cosmology of Extra Dimensions and Varying Fundamental Constants

I briefly present the Organizing Committee's and my own motivation for organizing this workshop, and I suggest a few key questions for which we will try to find possible answers in the coming days. This revised version was published online in July 2006 with corrections to the Cover Date.     

Rare earth, major and trace elements in Jurassic manganese shales of the Northern Calcareous Alps: hydrothermal versus hydrogenous origin of stratiform manganese deposits

Summary ?The rare earth, major and trace element geochemistry of Jurassic deep marine manganese shales allow insight into their environment of deposition. We present data of 24 samples from the Northern Calcareous Alps (Eastern Alps), collected from Late Jurassic strata of the Tennengebirge and from Early Jurassic strata of the Karwendel Mts. Whereas major and trace element geochemistry is controlled by the detrital input, rare earth element data and the relationship between total organic carbon and (pyritic) sulfur can be used to constrain the origin of the manganese accumulation. The data of this study are compatible with a hydrogenous precipitation of manganese by strongly varying redox-conditions at the sediment–water interface of a slope basin. Received December 21, 2001; revised version accepted February 18, 2002     

Amino acid analyses of Antarctic CM2 meteorites using liquid chromatography‐time of flight‐mass spectrometry

Abstract— Amino acid analyses of the Antarctic CM2 chondrites Allan Hills (ALH) 83100 and Lewis Cliff (LEW) 90500 using liquid chromatography‐time of flight‐mass spectrometry (LC‐ToF‐MS) coupled with UV fluorescence detection revealed that these carbonaceous meteorites contain a suite of indigenous amino acids not present in Antarctic ice. Several amino acids were detected in ALH 83100, including glycine, alanine, β‐alanine, γ‐amino‐n‐butyric acid (γ‐ABA), and α‐aminoisobutyric acid (AIB) with concentrations ranging from 250 to 340 parts per billion (ppb). In contrast to ALH 83100, the CM2 meteorites LEW 90500 and Murchison had a much higher total abundance of these amino acids (440–3200 ppb). In addition, ALH 83100 was found to have lower abundances of the α‐dialkyl amino acids AIB and isovaline than LEW 90500 and Murchison. There are three possible explanations for the depleted amino acid content in ALH 83100: 1) amino acid leaching from ALH 83100 during exposure to Antarctic ice meltwater, 2) a higher degree of aqueous alteration on the ALH 83100 parent body, or 3) ALH 83100 originated on a chemically distinct parent body from the other two CM2 meteorites. The high relative abundance of ?‐amino‐n‐caproic acid (EACA) in the ALH 83100 meteorite as well as the Antarctic ice indicates that Nylon‐6 contamination from the Antarctic sample storage bags may have occurred during collection.     

2D/3D Dust Continuum Radiative Transfer Codes to Analyze and Predict VLTI Observations

Radiative Transfer (RT) codes with image capability are a fundamental tool for preparing interferometric observations and for interpreting visibility data. In view of the upcoming VLTI facilities, we present the first comparison of images/visibilities coming from two 3D codes that use completely different techniques to solve the problem of self-consistent continuum RT. In addition, we focus on the astrophysical case of a disk distorted by tidal interaction with by-passing stars or internal planets and investigate for which parameters the distortion can be best detected in the mid-infrared using the mid-infrared interferometric device MIDI. This revised version was published online in July 2006 with corrections to the Cover Date.     

BRIGHTNESS VARIATIONS OF Mg Ib BRIGHT FEATURES

We study the temporal intensity variations of Mgib bright features and investigate the corresponding Hα velocity pattern. The network bright features are well visible in the continuum, in images averaged over the duration of the observations (130 min). We detected `flashing' bright features, which appear and disappear within two to five minutes, while the rest of the bright features undergo small variations of either their shape and/or their intensity. A power spectrum analysis reveals a 10-min oscillation for approximately half of the stable bright features. The 5-min oscillations are detected mainly at the network boundaries, where stable bright features are located, while 3-min oscillations coincide with few bright features, but are also quite intense inside the network cells. The majority of bright features are associated with Hα downflows. The downflow is very intense at the location of `flashing' bright features.     

Final tidal evolution of orbit-orbit resonances

In this paper we describe a model for the tidal evolution of an orbit-orbit resonance between two satellites of the same planet. We let the system evolve till infinity or until the resonance is destroyed. We find that there are asymptotic values for the eccentricities and inclinations. We list the possible final stages that a resonance can achieve, we give a few examples, and finally we discuss the limitations of the model and its possible applications to real systems.     

Exposure history of the Torino meteorite

Abstract— We determined He, Ne, Ar, ¹⁰Be, ²⁶Al, ³⁶Cl, and ¹⁴C concentrations, as well as cosmic-ray track densities and halogen concentrations in different specimens of the H6 chondrite Torino, in order to constrain its exposure history to cosmic radiation. The Torino meteoroid had a radius of ～20 cm and travelled in interplanetary space for 2.5–10 Ma. Earlier, Torino was part of a larger body. The smallest possible precursor had a radius of 55 cm and a journey through space longer than ～65 Ma. If the first-stage exposure took place in a body with a radius of >3 m or in the parent asteroid, then it lasted nearly 300 Ma. The example of Torino shows that it is easy to underestimate first-stage exposure ages when constructing two-stage histories.     

Influence of viscous dissipation on a hydromagnetic field

The effect of a transverse magnetic field and of the viscosity diffusion on the free-convection flow of an electrically-conducting incompressible fluid past a uniformally accelerated vertical plate is discussed. A finite difference method has been used to obtain a numerical solution. The influence of the various parameters on the flow field is discussed.