Onset of slow dynamics in difluorotetrachloroethane glassy crystal

Complementary Neutron Spin Echo and X-ray experiments and Molecular Dynamics simulations have been performed on difluorotetrachloroethane (CFCl2-CFCl2) glassy crystal. Static, single-molecule reorientational dynamics and collective dynamics properties are investigated. The orientational disorder is characterized at different temperatures and a change in nature of rotational dynamics is observed. We show that dynamics can be described by some scaling predictions of the Mode Coupling Theory (MCT) and a critical temperature $T_{c}$ is determined. Our results also confirm the strong analogy between molecular liquids and plastic crystals for which $\alpha$-relaxation times and non-ergodicity parameters are controlled by the non trivial static correlations as predicted by MCT

Evolution of optically faint AGN from COMBO-17 and GEMS

We have mapped the AGN luminosity function and its evolution between z=1 and z=5 down to apparent magnitudes of $R<24$. Within the GEMS project we have analysed HST-ACS images of many AGN in the Extended Chandra Deep Field South, enabling us to assess the evolution of AGN host galaxy properties with cosmic time.Comment: to appear in proceedings 'Multiwavelength AGN Surveys', Cozumel 200

Pace and Process of Active Folding and Fluvial Incision Across the Kantishna Hills Anticline, Central Alaska

Rates of northern Alaska Range thrust system deformation are poorly constrained. Shortening at the system\u27s west end is focused on the Kantishna Hills anticline. Where the McKinley River cuts across the anticline, the landscape records both Late Pleistocene deformation and climatic change. New optically stimulated luminescence and cosmogenic 10Be depth profile dates of three McKinley River terrace levels (~22, ~18, and ~14–9 ka) match independently determined ages of local glacial maxima, consistent with climate-driven terrace formation. Terrace ages quantify rates of differential bedrock incision, uplift, and shortening based on fault depth inferred from microseismicity. Differential rock uplift and incision (≤1.4 m/kyr) drive significant channel width narrowing in response to ongoing folding at a shortening rate of ~1.2 m/kyr. Our results constrain northern Alaska Range thrust system deformation rates, and elucidate superimposed landscape responses to Late Pleistocene climate change and active folding with broad geomorphic implications

GEMS Survey Data and Catalog

We describe the data reduction and object cataloging for the GEMS survey, a large-area (800 arcmin(2)) two-band (F606W and F850LP) imaging survey with the Advanced Camera for Surveys on the Hubble Space Telescope, centered on the Chandra Deep Field-South.STScI HST-GO-9500.01NASA GO-9500, NAS5-26555, NAG5-13063, NAG5-13102European Community’s Human Potential Programunder contractHPRN-CT-2002-00316, HPRN-CT-2002-00305McDonald Observator

Evidence for a correlation between the sizes of quiescent galaxies and local environment to z ~ 2

We present evidence for a strong relationship between galaxy size and environment for the quiescent population in the redshift range 1 < z < 2. Environments were measured using projected galaxy overdensities on a scale of 400 kpc, as determined from ~ 96,000 K-band selected galaxies from the UKIDSS Ultra Deep Survey (UDS). Sizes were determined from ground-based K-band imaging, calibrated using space-based CANDELS HST observations in the centre of the UDS field, with photometric redshifts and stellar masses derived from 11-band photometric fitting. From the resulting size-mass relation, we confirm that quiescent galaxies at a given stellar mass were typically ~ 50 % smaller at z ~ 1.4 compared to the present day. At a given epoch, however, we find that passive galaxies in denser environments are on average significantly larger at a given stellar mass. The most massive quiescent galaxies (M_stellar > 2 x 10^11 M_sun) at z > 1 are typically 50 % larger in the highest density environments compared to those in the lowest density environments. Using Monte Carlo simulations, we reject the null hypothesis that the size-mass relation is independent of environment at a significance > 4.8 sigma for the redshift range 1 < z < 2. In contrast, the evidence for a relationship between size and environment is much weaker for star-forming galaxies.Comment: Accepted for publication in MNRAS. 16 pages, 11 figures, 6 table

Thermotectonic History of the Kluane Ranges and Evolution of the Eastern Denali Fault Zone in Southwestern Yukon, Canada

Exhumation and landscape evolution along strike‐slip fault systems reflect tectonic processes that accommodate and partition deformation in orogenic settings. We present 17 new apatite (U‐Th)/He (He), zircon He, apatite fission‐track (FT), and zircon FT dates from the eastern Denali fault zone (EDFZ) that bounds the Kluane Ranges in Yukon, Canada. The dates elucidate patterns of deformation along the EDFZ. Mean apatite He, apatite FT, zircon He, and zircon FT sample dates range within ~26–4, ~110–12, ~94–28, and ~137–83 Ma, respectively. A new zircon U‐Pb date of 113.9 ± 1.7 Ma (2σ) complements existing geochronology and aids in interpretation of low‐temperature thermochronometry data patterns. Samples ≤2 km southwest of the EDFZ trace yield the youngest thermochronometry dates. Multimethod thermochronometry, zircon He date‐effective U patterns, and thermal history modeling reveal rapid cooling ~95–75 Ma, slow cooling ~75–30 Ma, and renewed rapid cooling ~30 Ma to present. The magnitude of net surface uplift constrained by published paleobotanical data, exhumation, and total surface uplift from ~30 Ma to present are ~1, ~2–6, and ~1–7 km, respectively. Exhumation is highest closest to the EDFZ trace but substantially lower than reported for the central Denali fault zone. We infer exhumation and elevation changes associated with ~95–75 Ma terrane accretion and EDFZ activity, relief degradation from ~75–30 Ma, and ~30 Ma to present exhumation and surface uplift as a response to flat‐slab subduction and transpressional deformation. Integrated results reveal new constraints on landscape evolution within the Kluane Ranges directly tied to the EDFZ during the last ~100 Myr

Cluster Performance reconsidered: Structure, Linkages and Paths in the German Biotechnology Industry, 1996-2003

This paper addresses the evolution of biotechnology clusters in Germany between 1996 and 2003, paying particular attention to their respective composition in terms of venture capital, basic science institutions and biotechnology firms. Drawing upon the significance of co-location of "money and ideas", the literature stressing the importance of a cluster's openness and external linkages, and the path dependency debate, the paper aims to analyse how certain cluster characteristics correspond with its overall performance. After identifying different cluster types, we investigate their internal and external interconnectivity in comparative manner and draw on changes in cluster composition. Our results indicate that the structure, i.e. to which group the cluster belongs, and the openness towards external knowledge flows deliver merely unsystematic indications with regard to a cluster's overall success. Its ability to change composition towards a more balanced ratio of science and capital over time, on the other hand, turns out as a key explanatory factor. Hence, the dynamic perspective proves effective illuminating cluster growth and performance, where our explorative findings provide a promising avenue for further evolutionary research

Structural parameters of galaxies in CANDELS

We present global structural parameter measurements of 109,533 unique, H-F160W-selected objects from the CANDELS multi-cycle treasury program. Sersic model fits for these objects are produced with GALFIT in all available near-infrared filters (H-F160W, J(F125W) and, for a subset, Y-F105W). The parameters of the best-fitting Sersic models (total magnitude, half-light radius, Sersic index, axis ratio, and position angle) are made public, along with newly constructed point-spread functions for each field and filter. Random uncertainties in the measured parameters are estimated for each individual object based on a comparison between multiple, independent measurements of the same set of objects. To quantify systematic uncertainties, we create a mosaic with simulated galaxy images with a realistic distribution of input parameters and then process and analyze the mosaic in an identical manner as the real data. We find that accurate and precise measurements-to 10% or better-of all structural parameters can typically be obtained for galaxies with H-F160W < 23, with comparable fidelity for basic size and shape measurements for galaxies to H-F160W similar to 24.5

A weak lensing estimate from GEMS of the virial to stellar mass ratio in massive galaxies to z~0.8

We present constraints on the evolution of the virial to stellar mass ratio of galaxies with high stellar masses in the redshift range 0.2<z<0.8, by comparing weak lensing measurements of virial mass M_vir to estimates of stellar mass M_star from COMBO-17. For a complete sample of galaxies with log(M_star/ M_\odot) > 10.5, where the majority show an early-type morphology, we find that the virial mass to stellar mass ratio is given by M_vir/M_star = 53^{+13}_{-16}. Assuming a baryon fraction from the concordance cosmology, this corresponds to a stellar fraction of baryons in massive galaxies of Omega_b^*/\Omega_b = 0.10 +/- 0.03. Analysing the galaxy sample in different redshift slices, we find little or no evolution in the virial to stellar mass ratio, and place an upper limit of ~2.5 on the growth of massive galaxies through the conversion of gas into stars from z=0.8 to the present day.Comment: 5 pages, 2 figures, to appear in MNRAS Letters. Version includes referee comment